@@ -40,7 +40,7 @@ See the [sources](#sources) and [selection criteria](#selection-criteria) below.
 1. **Engineering a Sort Function. [Bentley, McIlroy (1993)](https://cs.fit.edu/~pkc/classes/writing/samples/bentley93engineering.pdf).**
     \
     <sub>Data Structures; Algorithms</sub>
-    * On the Shortest Spanning Subtree of a Graph and the Traveling Salesman Problem. [Kruskal (1956)](https://www.ams.org/proc/1956-007-01/S0002-9939-1956-0078686-7/S0002-9939-1956-0078686-7.pdf).
+    * On the Shortest Spanning Subtree of a Graph and the Traveling Salesman Problem. [Kruskal (1956)](https://www.cs.yale.edu/homes/lans/readings/routing/kruskal-1956.pdf).
     * A Note on Two Problems in Connexion with Graphs. [Dijkstra (1959)](https://jmvidal.cse.sc.edu/library/dijkstra59a.pdf).
     * Quicksort. [Hoare (1962)](https://dl.acm.org/doi/pdf/10.5555/63445.C1104357).
     * Space/Time Trade-offs in Hash Coding with Allowable Errors. [Bloom (1970)](https://dl.acm.org/doi/pdf/10.1145/362686.362692).
@@ -262,7 +262,7 @@ See the [sources](#sources) and [selection criteria](#selection-criteria) below.
 1. Prediction and Entropy of Printed English. [Shannon (1950)](https://www.princeton.edu/~wbialek/rome/refs/shannon_51.pdf).
 1. The Education of a Computer. [Hopper (1952)](https://people.cs.umass.edu/~emery/classes/cmpsci691st/readings/PL/p243-hopper.pdf).
 1. **A Method for the Construction of Minimum-Redundancy Codes. [Huffman (1952)](http://compression.ru/download/articles/huff/huffman_1952_minimum-redundancy-codes.pdf).**
-1. On the Shortest Spanning Subtree of a Graph and the Traveling Salesman Problem. [Kruskal (1956)](https://www.ams.org/proc/1956-007-01/S0002-9939-1956-0078686-7/S0002-9939-1956-0078686-7.pdf).
+1. On the Shortest Spanning Subtree of a Graph and the Traveling Salesman Problem. [Kruskal (1956)](https://www.cs.yale.edu/homes/lans/readings/routing/kruskal-1956.pdf).
 1. Man-Computer symbiosis. [Licklider (1958)](http://worrydream.com/refs/Licklider%20-%20Man-Computer%20Symbiosis.pdf).
 1. A Note on Two Problems in Connexion with Graphs. [Dijkstra (1959)](https://jmvidal.cse.sc.edu/library/dijkstra59a.pdf).
 1. Recursive Programming. [Dijkstra (1960)](https://www.ics.uci.edu/~jajones/INF102-S18/readings/07_dijkstra.pdf).
 
@@ -104,7 +104,7 @@
     - title: On the Shortest Spanning Subtree of a Graph and the Traveling Salesman Problem
       author: Kruskal
       year: 1956
-      link: https://www.ams.org/proc/1956-007-01/S0002-9939-1956-0078686-7/S0002-9939-1956-0078686-7.pdf
+      link: https://www.cs.yale.edu/homes/lans/readings/routing/kruskal-1956.pdf
     - title: A Note on Two Problems in Connexion with Graphs
       author: Dijkstra
       year: 1959