diff --git a/README.md b/README.md
index b758a3b..5c42e6f 100644
--- a/README.md
+++ b/README.md
@@ -154,6 +154,18 @@ e.g. write to `neo4j://localhost:7687`:
 python -m dblp_crawler -k video -k edge -p 27d5dc70280c8628f181a7f8881912025f808256 -a 1681457 neo4j --uri neo4j://localhost:7687
 ```
 
+#### Tips
+
+Without index, NEO4J query will be very very slow. So before you start, you should add some index:
+
+```cql
+CREATE INDEX publication_title_hash_index FOR (p:Publication) ON (p.title_hash);
+CREATE INDEX publication_dblp_key_index FOR (p:Publication) ON (p.dblp_key);
+CREATE INDEX publication_paper_id_index FOR (p:Publication) ON (p.paperId);
+CREATE INDEX person_author_id_index FOR (p:Person) ON (p.authorId);
+CREATE INDEX person_dblp_pid_index FOR (p:Person) ON (p.dblp_pid);
+```
+
 ### Get initial paper list or author list from a Neo4J database
 
 ```sh
diff --git a/setup.py b/setup.py
index d8c12c4..96e07b6 100644
--- a/setup.py
+++ b/setup.py
@@ -15,7 +15,7 @@
 
 setup(
     name='citation_crawler',
-    version='2.5.3',
+    version='2.7',
     author='yindaheng98',
     author_email='yindaheng98@gmail.com',
     url='https://github.com/yindaheng98/citation-crawler',