1. CVC4-1.5. http://cvc4.cs.stanford.edu/web/ . Accessed 14 Jun 2018
2. Norn. http://user.it.uu.se/jarst116/norn/ . Accessed 14 June 2018
3. S3P. http://www.comp.nus.edu.sg/trinhmt/S3/S3P-bin-090817.zip . Accessed 20 Jan 2018
4. TRAU. https://github.com/diepbp/fat . Accessed 10 June 2018
5. Z3str3. https://sites.google.com/site/z3strsolver/getting-started . Accessed 14 June 2018