diff --git a/server/database.py b/server/database.py
index c4f5fc6..f47b37e 100644
--- a/server/database.py
+++ b/server/database.py
@@ -57,6 +57,27 @@ async def retrieve_search_result_by_id(id_: str):
         return
 
 
+async def delete_search_result_by_id(id_: str):
+    """Delete concrete article in a database by ID"""
+    try:
+        result = await search_results_collection.delete_one({"_id": ObjectId(id_)})
+        if result:
+            return True
+    except InvalidId:
+        pass
+    return False
+
+
+async def retrieve_authors_count_of_articles():
+    """Retrieve count of articles for each author"""
+    group_by_author = {"$group": {"_id": "$author", "count_of_articles": {"$sum": 1}}}
+    sort_by_count_desc = {"$sort": {"count_of_articles": -1}}
+    pipeline = [group_by_author, sort_by_count_desc]
+    articles_count = search_results_collection.aggregate(pipeline)
+    articles_count = await articles_count.to_list(length=None)
+    return articles_count
+
+
 async def retrieve_search_results_by_tags(tags: list[str], page: int, limit: int, period: Period):
     """Find articles by tags