diff --git a/search_app.py b/search_app.py
index 5a88482..c0ecd39 100644
--- a/search_app.py
+++ b/search_app.py
@@ -286,6 +286,24 @@ def parse_channel_params(values: Iterable[Optional[str]]) -> List[str]:
     return channels
 
 
+def build_year_filter(year: Optional[str]) -> Optional[Dict]:
+    if not year:
+        return None
+    try:
+        year_int = int(year)
+        return {
+            "range": {
+                "date": {
+                    "gte": f"{year_int}-01-01",
+                    "lt": f"{year_int + 1}-01-01",
+                    "format": "yyyy-MM-dd"
+                }
+            }
+        }
+    except (ValueError, TypeError):
+        return None
+
+
 def build_channel_filter(channels: Optional[Sequence[str]]) -> Optional[Dict]:
     if not channels:
         return None
@@ -320,6 +338,7 @@ def build_query_payload(
     query: str,
     *,
     channels: Optional[Sequence[str]] = None,
+    year: Optional[str] = None,
     sort: str = "relevant",
     use_exact: bool = True,
     use_fuzzy: bool = True,
@@ -333,6 +352,10 @@ def build_query_payload(
     if channel_filter:
         filters.append(channel_filter)
 
+    year_filter = build_year_filter(year)
+    if year_filter:
+        filters.append(year_filter)
+
     if use_query_string:
         base_fields = ["title^3", "description^2", "transcript_full", "transcript_secondary_full"]
         qs_query = (query or "").strip() or "*"
@@ -376,6 +399,8 @@ def build_query_payload(
             body["sort"] = [{"date": {"order": "desc"}}]
         elif sort == "older":
             body["sort"] = [{"date": {"order": "asc"}}]
+        elif sort == "referenced":
+            body["sort"] = [{"referenced_by_count": {"order": "desc"}}]
         return body
 
     if query:
@@ -479,6 +504,8 @@ def build_query_payload(
         body["sort"] = [{"date": {"order": "desc"}}]
     elif sort == "older":
         body["sort"] = [{"date": {"order": "asc"}}]
+    elif sort == "referenced":
+        body["sort"] = [{"referenced_by_count": {"order": "desc"}}]
     return body
 
 
@@ -570,6 +597,53 @@ def create_app(config: AppConfig = CONFIG) -> Flask:
         data.sort(key=lambda item: item["Name"].lower())
         return jsonify(data)
 
+    @app.route("/api/years")
+    def years():
+        body = {
+            "size": 0,
+            "aggs": {
+                "years": {
+                    "date_histogram": {
+                        "field": "date",
+                        "calendar_interval": "year",
+                        "format": "yyyy",
+                        "order": {"_key": "desc"}
+                    }
+                }
+            }
+        }
+
+        if config.elastic.debug:
+            LOGGER.info(
+                "Elasticsearch years request: %s",
+                json.dumps({"index": index, "body": body}, indent=2),
+            )
+
+        response = client.search(index=index, body=body)
+
+        if config.elastic.debug:
+            LOGGER.info(
+                "Elasticsearch years response: %s",
+                json.dumps(response, indent=2, default=str),
+            )
+
+        buckets = (
+            response.get("aggregations", {})
+            .get("years", {})
+            .get("buckets", [])
+        )
+
+        data = [
+            {
+                "Year": bucket.get("key_as_string"),
+                "Count": bucket.get("doc_count", 0),
+            }
+            for bucket in buckets
+            if bucket.get("doc_count", 0) > 0
+        ]
+
+        return jsonify(data)
+
     @app.route("/api/search")
     def search():
         query = request.args.get("q", "", type=str)
@@ -578,6 +652,7 @@ def create_app(config: AppConfig = CONFIG) -> Flask:
         if legacy_channel:
             raw_channels.append(legacy_channel)
         channels = parse_channel_params(raw_channels)
+        year = request.args.get("year", "", type=str) or None
         sort = request.args.get("sort", "relevant", type=str)
         page = max(request.args.get("page", 0, type=int), 0)
         size = max(request.args.get("size", 10, type=int), 1)
@@ -598,6 +673,7 @@ def create_app(config: AppConfig = CONFIG) -> Flask:
         payload = build_query_payload(
             query,
             channels=channels,
+            year=year,
             sort=sort,
             use_exact=use_exact,
             use_fuzzy=use_fuzzy,
@@ -671,6 +747,8 @@ def create_app(config: AppConfig = CONFIG) -> Flask:
                         "primary": bool(highlight_map.get("transcript_full")),
                         "secondary": bool(highlight_map.get("transcript_secondary_full")),
                     },
+                    "internal_references_count": source.get("internal_references_count", 0),
+                    "referenced_by_count": source.get("referenced_by_count", 0),
                 }
             )
 
@@ -716,6 +794,7 @@ def create_app(config: AppConfig = CONFIG) -> Flask:
         if legacy_channel:
             raw_channels.append(legacy_channel)
         channels = parse_channel_params(raw_channels)
+        year = request.args.get("year", "", type=str) or None
         interval = (request.args.get("interval", "month") or "month").lower()
         allowed_intervals = {"day", "week", "month", "quarter", "year"}
         if interval not in allowed_intervals:
@@ -727,6 +806,9 @@ def create_app(config: AppConfig = CONFIG) -> Flask:
         channel_filter = build_channel_filter(channels)
         if channel_filter:
             filters.append(channel_filter)
+        year_filter = build_year_filter(year)
+        if year_filter:
+            filters.append(year_filter)
         if start or end:
             range_filter: Dict[str, Dict[str, Dict[str, str]]] = {"range": {"date": {}}}
             if start:
diff --git a/static/app.js b/static/app.js
index 9c564f3..faaeb0c 100644
--- a/static/app.js
+++ b/static/app.js
@@ -35,6 +35,7 @@
   const channelDropdown = document.getElementById("channelDropdown");
   const channelSummary = document.getElementById("channelSummary");
   const channelOptions = document.getElementById("channelOptions");
+  const yearSel = document.getElementById("year");
   const sortSel = document.getElementById("sort");
   const sizeSel = document.getElementById("size");
   const exactToggle = document.getElementById("exactToggle");
@@ -140,8 +141,29 @@
     }
   }
 
+  async function loadYears() {
+    if (!yearSel) return;
+    try {
+      const res = await fetch("/api/years");
+      const data = await res.json();
+
+      // Keep the "All Years" option
+      yearSel.innerHTML = '<option value="">All Years</option>';
+
+      data.forEach((item) => {
+        const option = document.createElement("option");
+        option.value = item.Year;
+        option.textContent = `${item.Year} (${item.Count})`;
+        yearSel.appendChild(option);
+      });
+    } catch (err) {
+      console.error("Failed to load years", err);
+    }
+  }
+
   function setFromQuery() {
     qInput.value = qs.get("q") || "";
+    yearSel.value = qs.get("year") || "";
     sortSel.value = qs.get("sort") || "relevant";
     sizeSel.value = qs.get("size") || "10";
     pendingChannelSelection = parseChannelParams(qs);
@@ -305,13 +327,18 @@
     }
   }
 
-  function updateUrl(q, sort, channels, page, size, exact, fuzzy, phrase, queryMode) {
+  function updateUrl(q, sort, channels, year, page, size, exact, fuzzy, phrase, queryMode) {
     const next = new URL(window.location.href);
     next.searchParams.set("q", q);
     next.searchParams.set("sort", sort);
     next.searchParams.delete("channel_id");
     next.searchParams.delete("channel");
     channels.forEach((id) => next.searchParams.append("channel_id", id));
+    if (year) {
+      next.searchParams.set("year", year);
+    } else {
+      next.searchParams.delete("year");
+    }
     next.searchParams.set("page", page);
     next.searchParams.set("size", size);
     next.searchParams.set("exact", exact ? "1" : "0");
@@ -893,7 +920,7 @@ function renderFrequencyChart(buckets, channelTotals) {
   freqChart.appendChild(legend);
 }
 
-async function updateFrequencyChart(term, channels, queryMode) {
+async function updateFrequencyChart(term, channels, year, queryMode) {
   if (!freqChart || typeof d3 === "undefined") {
     return;
   }
@@ -911,6 +938,9 @@ async function updateFrequencyChart(term, channels, queryMode) {
   params.set("term", trimmed);
   params.set("interval", "month");
   (channels || []).forEach((id) => params.append("channel_id", id));
+  if (year) {
+    params.set("year", year);
+  }
   if (queryMode) {
     params.set("query_string", "1");
   }
@@ -961,6 +991,13 @@ async function updateFrequencyChart(term, channels, queryMode) {
       const badges = [];
       if (item.highlightSource && item.highlightSource.primary) badges.push('primary transcript');
       if (item.highlightSource && item.highlightSource.secondary) badges.push('secondary transcript');
+
+      // Add reference count badges
+      const refByCount = item.referenced_by_count || 0;
+      const refToCount = item.internal_references_count || 0;
+      if (refByCount > 0) badges.push(`${refByCount} backlink${refByCount !== 1 ? 's' : ''}`);
+      if (refToCount > 0) badges.push(`${refToCount} reference${refToCount !== 1 ? 's' : ''}`);
+
       const badgeHtml = badges.length
         ? `<div class="badge-row">${badges
             .map((b) => `<span class="badge">${escapeHtml(b)}</span>` )
@@ -1041,6 +1078,7 @@ async function updateFrequencyChart(term, channels, queryMode) {
   async function runSearch(pageOverride, pushState = true) {
     const q = qInput.value.trim();
     const channels = getSelectedChannels();
+    const year = yearSel.value;
     const sort = sortSel.value;
     const size = parseInt(sizeSel.value, 10) || 10;
     const queryMode = queryToggle && queryToggle.checked;
@@ -1062,7 +1100,7 @@ async function updateFrequencyChart(term, channels, queryMode) {
     currentPage = page;
 
     if (pushState) {
-      updateUrl(q, sort, channels, page, size, exact, fuzzy, phrase, queryMode);
+      updateUrl(q, sort, channels, year, page, size, exact, fuzzy, phrase, queryMode);
     }
 
     const params = new URLSearchParams();
@@ -1075,17 +1113,19 @@ async function updateFrequencyChart(term, channels, queryMode) {
     params.set("phrase", phrase ? "1" : "0");
     params.set("query_string", queryMode ? "1" : "0");
     channels.forEach((id) => params.append("channel_id", id));
+    if (year) params.set("year", year);
 
     const res = await fetch(`/api/search?${params.toString()}`);
     const payload = await res.json();
     renderResults(payload, page);
-    updateFrequencyChart(q, channels, queryMode);
+    updateFrequencyChart(q, channels, year, queryMode);
   }
 
 searchBtn.addEventListener("click", () => runSearch(0));
   qInput.addEventListener("keypress", (e) => {
     if (e.key === "Enter") runSearch(0);
   });
+  yearSel.addEventListener("change", () => runSearch(0));
   sortSel.addEventListener("change", () => runSearch(0));
   sizeSel.addEventListener("change", () => runSearch(0));
   exactToggle.addEventListener("change", () => { rememberToggleState(); runSearch(0); });
@@ -1104,6 +1144,7 @@ window.addEventListener("popstate", () => {
 
   setFromQuery();
   loadMetrics();
+  loadYears();
   loadChannels().then(() => runSearch(currentPage));
 })();
 
diff --git a/static/index.html b/static/index.html
index 4b1f4fc..54b877f 100644
--- a/static/index.html
+++ b/static/index.html
@@ -38,11 +38,17 @@
               </div>
             </details>
 
+            <label for="year" style="margin-left: 8px;">Year:</label>
+            <select id="year">
+              <option value="">All Years</option>
+            </select>
+
             <label for="sort" style="margin-left: 8px;">Sort:</label>
             <select id="sort">
               <option value="relevant">Most relevant</option>
               <option value="newer">Newest first</option>
               <option value="older">Oldest first</option>
+              <option value="referenced">Most referenced</option>
             </select>
 
             <label for="size" style="margin-left: 8px;">Size:</label>