Cancellation in a Parallel Semantic Network. - Scott E. Fahlman; David S. Touretzky; Walter van Roggen (IJCAI, 1981)

Successful visual and end-user programming systems from industry. - Brad A. Myers; Alexander Repenning; Peter Lucas 002; Walter van Roggen; Allen Cypher; Andrew P. Dove; Ofer Brandes (VL/HCC, 2011)