diff --git a/generic_rag/graphs/ret_gen.py b/generic_rag/graphs/ret_gen.py
index f7f1fae..c6f58d3 100644
--- a/generic_rag/graphs/ret_gen.py
+++ b/generic_rag/graphs/ret_gen.py
@@ -1,3 +1,4 @@
+from pathlib import Path
 from typing import Any, Union
 
 from langchain import hub
@@ -32,7 +33,7 @@ class RetGenLangGraph:
     def invoke(self, message: str, config: dict) -> Union[dict[str, Any], Any]:
         self.last_invoke = self.graph.invoke({"question": message}, config=config)
         return self.last_invoke["answer"]
-    
+
     def _retrieve(self, state: State) -> dict:
         retrieved_docs = self.vector_store.similarity_search(state["question"])
         return {"context": retrieved_docs}
@@ -49,19 +50,33 @@ class RetGenLangGraph:
         """
         if self.last_invoke is None:
             return []
-        
+
         pdf_sources = {}
         for context in self.last_invoke["context"]:
             try:
-                if context.metadata["filetype"] == "application/pdf":
-                    source = context.metadata["source"]
-                    page_number = context.metadata["page_number"]
-                    if source in pdf_sources:
-                        pdf_sources[source].add(page_number)
-                    else:
-                        pdf_sources[source] = {page_number}
+                Path(context.metadata["source"]).suffix == ".pdf"
+            except KeyError:
+                continue
+            else:
+                source = context.metadata["source"]
+
+            if source not in pdf_sources:
+                pdf_sources[source] = set()
+
+            # The page numbers are in the `page_numer` and `page` fields.
+            try:
+                page_number = context.metadata["page_number"]
             except KeyError:
                 pass
+            else:
+                pdf_sources[source].add(page_number)
+
+            try:
+                page_number = context.metadata["page"]
+            except KeyError:
+                pass
+            else:
+                pdf_sources[source].add(page_number)
 
         return pdf_sources
 
@@ -71,13 +86,14 @@ class RetGenLangGraph:
         """
         if self.last_invoke is None:
             return set()
-        
+
         web_sources = set()
         for context in self.last_invoke["context"]:
             try:
-                if context.metadata["filetype"] == "web":
-                    web_sources.add(context.metadata["source"])
+                context.metadata["filetype"] == "web"
             except KeyError:
-                pass
+                continue
+            else:
+                web_sources.add(context.metadata["source"])
 
         return web_sources