Marcelo Sihman Shmuel Katz Superimpositions and Aspect-oriented Programming. 529-541 2003 46 Comput. J. 5 http://www3.oup.co.uk/computer_journal/hdb/Volume_46/Issue_05/460529.sgm.abs.html db/journals/cj/cj46.html#SihmanK03