Lau-Kee, D., Billyard, A., Faice R., Kozato, Y., Otto, P., Smith, M., Wilkinson, L "VPL: An Active, Declarative Visual Programming System"

Proc. (1991) Proc. of the 1991 IEEE Workshop on Visual Languages, Kobe, Japan, October 1991  

Languages mentioned VPL {1991}