Steve M. Easterbrook Robyn R. Lutz Richard Covington John Kelly Yoko Ampo David Hamilton Experiences Using Lightweight Formal Methods for Requirements Modeling. 4-14 http://csdl.computer.org/comp/trans/ts/1998/01/e0004abs.htm 1998 24 IEEE Trans. Software Eng. 1 db/journals/tse/tse24.html#EasterbrookLCKAH98