Toufik Taibi Fathi Taibi Formal Specification of Design Patterns and Their Instances. 33-36 2006 AICCSA http://ieeexplore.ieee.org/xpls/abs_all.jsp?isnumber=33913&arnumber=1618329&count=182&index=4 conf/aiccsa/2006 db/conf/aiccsa/aiccsa2006.html#TaibiT06