fix quick check paper link

README.md

@@ -74,7 +74,7 @@ See the [sources](#sources) and [selection criteria](#selection-criteria) below.
  * Can Programming Be Liberated from the von Neumann Style? [Backus (1978)](https://dl.acm.org/doi/pdf/10.1145/359576.359579).
  * The Semantic Elegance of Applicative Languages. [Turner (1981)](http://nsl.com/misc/sasl/paraffins-turner.pdf).
  * The essence of functional programming. [Wadler (1992)](https://dl.acm.org/doi/pdf/10.1145/143165.143169).
- * QuickCheck: A Lightweight Tool for Random Testing of Haskell Programs. [Claessen, Hughes (2000)](https://www.cs.tufts.edu/~nr/cs257/archive/john-hughes/quick.pdf).
+ * QuickCheck: A Lightweight Tool for Random Testing of Haskell Programs. [Claessen, Hughes (2000)](https://dl.acm.org/doi/pdf/10.1145/351240.351266).
  * Church's Thesis and Functional Programming. [Turner (2006)](https://kar.kent.ac.uk/88944/1/ctfp.pdf_nocoversheet).
 
 1. **An Incremental Approach to Compiler Construction. [Ghuloum (2006)](http://scheme2006.cs.uchicago.edu/11-ghuloum.pdf).**
@@ -365,7 +365,7 @@ See the [sources](#sources) and [selection criteria](#selection-criteria) below.
 1. Operational transformation in real-time group editors: issues, algorithms, and achievements. [Sun, Ellis (1998)](https://dl.acm.org/doi/pdf/10.1145/289444.289469).
 1. Rules of Thumb in Data Engineering. [Gray, Shenay (1999)](http://research.microsoft.com/en-us/um/people/gray/papers/ms_tr_99_100_rules_of_thumb_in_data_engineering.pdf).
 1. Practical Byzantine Fault Tolerance. [Castro, Liskov (1999)](https://pmg.csail.mit.edu/papers/osdi99.pdf).
-1. QuickCheck: A Lightweight Tool for Random Testing of Haskell Programs. [Claessen, Hughes (2000)](https://www.cs.tufts.edu/~nr/cs257/archive/john-hughes/quick.pdf).
+1. QuickCheck: A Lightweight Tool for Random Testing of Haskell Programs. [Claessen, Hughes (2000)](https://dl.acm.org/doi/pdf/10.1145/351240.351266).
 1. Paxos made simple. [Lamport (2001)](https://lamport.azurewebsites.net/pubs/paxos-simple.pdf).
 1. Statistical Modeling: The Two Cultures. [Breiman (2001)](https://projecteuclid.org/journalArticle/Download?urlId=10.1214%2Fss%2F1009213726).
 1. Recovery Oriented Computing (ROC): Motivation, Definition, Techniques, and Case Studies. [Patterson et al (2002)](http://www2.eecs.berkeley.edu/Pubs/TechRpts/2002/CSD-02-1175.pdf).

papers.yml

@@ -193,7 +193,7 @@
  - title: "QuickCheck: A Lightweight Tool for Random Testing of Haskell Programs"
  author: Claessen, Hughes
  year: 2000
- link: https://www.cs.tufts.edu/~nr/cs257/archive/john-hughes/quick.pdf
+ link: https://dl.acm.org/doi/pdf/10.1145/351240.351266
  - title: The essence of functional programming
  author: Wadler
  year: 1992