1. Alloy GitHub repository, 2019. https://github.com/AlloyTools/org.alloytools.alloy .
2. Alloy models repository, 2019. https://github.com/AlloyTools/models .
3. BreakID BitBucket repository, 2019. https://bitbucket.org/krr/breakid/src/master/ .
4. Kodkod examples repository, 2019. https://github.com/emina/kodkod/tree/master/examples .
5. Kodkod GitHub repository, 2019. https://github.com/emina/kodkod .