1. Program verification using HOL-UNITY;Andersen,1993
2. Refinement Calculus: A Systematic Introduction;Back,1998
3. Locales and locale expressions in Isabelle/Isar;Ballarin,2004
4. Interpretation of locales in Isabelle: Theories and proof contexts;Ballarin,2006
5. Proving pointer programs in Hoare Logic;Bornat,2000