1. Adams, M.: HOL Zero,
http://www.proof-technologies.com/holzero/
2. Arthan, R., Jones, R.B.: Z in HOL in ProofPower. BCS FACS FACTS (2005-1),
http://www.lemma-one.com/ProofPower/index/
3. Lecture Notes in Computer Science;J. Harrison,2009
4. Lecture Notes in Computer Science;P.V. Homeier,2009
5. LNAI;R. Kumar,2014