diff --git a/notes.md b/notes.md
index 126c0b2..d58b940 100644
--- a/notes.md
+++ b/notes.md
@@ -33,6 +33,6 @@
 
 ## [mapreduce](https://static.googleusercontent.com/media/research.google.com/en//archive/mapreduce-osdi04.pdf)
 
-## [spark](https://people.eecs.berkeley.edu/~matei/papers/2016/cacm_apache_spark.pdf)
+## [spark](https://www.usenix.org/system/files/conference/nsdi12/nsdi12-final138.pdf)
 
 ## [rpc](https://www.h3c.com/en/Support/Resource_Center/EN/Home/Switches/00-Public/Trending/Technology_White_Papers/gRPC_Technology_White_Paper-6W100/)