Jim Davies Charles Crichton Edward Crichton David Neilson Ib Holm Sørensen Formality, Evolution, and Model-driven Software Engineering. 39-55 2005 130 Electr. Notes Theor. Comput. Sci. http://dx.doi.org/10.1016/j.entcs.2005.03.004 db/journals/entcs/entcs130.html#DaviesCCNS05