1. http://verify.inf.usi.ch/content/lattice-refinement
2. https://scm.ti-edu.ch/projects/hifrog/
3. The coq proof assistant. https://coq.inria.fr/
4. Competition on software verification (SV-COMP) (2017). https://sv-comp.sosy-lab.org/2017/
5. Lecture Notes in Computer Science;L Alt,2017