diff --git a/README.md b/README.md
index 94429f2..3e93fd3 100644
--- a/README.md
+++ b/README.md
@@ -45,7 +45,7 @@ Some examples you could use the Aho-Corasick algorithm for:
 
 This library is the Java implementation of the afore-mentioned Aho-Corasick algorithm for efficient string matching.
 The algorithm is explained in great detail in the white paper written by
-Aho and Corasick: ftp://im1.im.tku.edu.tw/assistant/bearhero/prog/%E5%85%B6%E5%AE%83/ac_bm.pdf
+Aho and Corasick: http://cr.yp.to/bib/1975/aho.pdf
 
 Usage
 -----
diff --git a/src/main/java/org/ahocorasick/trie/Trie.java b/src/main/java/org/ahocorasick/trie/Trie.java
index fee5211..ed70c0f 100644
--- a/src/main/java/org/ahocorasick/trie/Trie.java
+++ b/src/main/java/org/ahocorasick/trie/Trie.java
@@ -13,7 +13,7 @@ import java.util.concurrent.LinkedBlockingDeque;
 
 /**
  *
- * Based on the Aho-Corasick white paper, Bell technologies: ftp://im1.im.tku.edu.tw/assistant/bearhero/prog/%E5%85%B6%E5%AE%83/ac_bm.pdf
+ * Based on the Aho-Corasick white paper, Bell technologies: http://cr.yp.to/bib/1975/aho.pdf
  * @author Robert Bor
  */
 public class Trie {