Kathleen Brade Mark Guzdial Mark Steckel Elliot Soloway Whorf: a Hypertext Tool for Software Maintenance. 1-16 1994 4 International Journal of Software Engineering and Knowledge Engineering 1 http://dx.doi.org/10.1142/S0218194094000027 db/journals/ijseke/ijseke4.html#BradeGSS94