Roger Attias Jacques-Emile Dubois Substructure systems: concepts and classifications. 2-7 1990 30 Journal of Chemical Information and Computer Sciences 1 http://pubs.acs.org/cgi-bin/archive.cgi/jcisd8/1990/30/i01/f-pdf/f_ci00065a002.pdf db/journals/jcisd/jcisd30.html#AttiasD90