Grading student programs using ASSYST. - David Jackson; Michelle M. Usher (SIGCSE, 1997)

A Petri net based visual programming language. - Michelle M. Usher; David Jackson (SMC, 1998)

A Concurrent Visual Language Based on Petri Nets. - Michelle M. Usher; David Jackson (VL, 1998)

Visualising Complex Sequential and Parallel Programs. - Mark A. Beaumont; David Jackson; Michelle M. Usher (Visual Representations and Interpretations, 1999)

A concurrent visual language based on Petri nets. - Michelle M. Usher (1999)

Promoting Scalability in a Concurrent Visual Language. - Michelle M. Usher; David Jackson (VL, 2000)