Peter Gorm Larsen John S. Fitzgerald Steve Riddle Practice-oriented courses in formal methods using VDM<sup>++</sup>. 245-257 2009 21 Formal Asp. Comput. 3 http://dx.doi.org/10.1007/s00165-008-0068-5 db/journals/fac/fac21.html#LarsenFR09