diff --git a/contents/algorithms/introduction.md b/contents/algorithms/introduction.md
index 1097ebaa..f58d72a8 100644
--- a/contents/algorithms/introduction.md
+++ b/contents/algorithms/introduction.md
@@ -53,6 +53,5 @@ If you want more structured algorithms practice, I recommend [Educative's Grokki
 
 - [Educative's Grokking the Coding Interview: Patterns for Coding Questions](https://www.educative.io/courses/grokking-the-coding-interview?aff=x23W)
 - http://blog.triplebyte.com/how-to-pass-a-programming-interview
-- https://quip.com/q41AA3OmoZbC
 - http://www.geeksforgeeks.org/must-do-coding-questions-for-companies-like-amazon-microsoft-adobe/
 - https://medium.com/basecs