Keiko Kawabe Akihiko Matsuo Sanya Uehara Akira Ogawa Interactive Variable Classification Technique to Support the Maintenance of COBOL Business Application Systems. 500-506 1999 conf/apsec/1999 APSEC http://csdl.computer.org/comp/proceedings/apsec/1999/0509/00/05090500abs.htm db/conf/apsec/apsec1999.html#KawabeMUO99