Eljas Soisalon-Soininen Inessential Error Entries and Their Use in LR Parser Optimization. 179-195 1982 4 ACM Trans. Program. Lang. Syst. 2 http://doi.acm.org/10.1145/357162.357165 db/journals/toplas/toplas4.html#Soisalon-Soininen82