[ACM] CACM 16(03) March 1973

(1957) Communications of the ACM  

Cárdenas, Alfonso F. and Karplus, Walter J. (1970) Cárdenas, Alfonso F. and Karplus, Walter J. "PDEL A Language for Partial Diferential Equations" Conway, Richard W. and Wilcox, Thomas R. (1973) Conway, Richard W. and Wilcox, Thomas R. "Design and implementation of a diagnostic compiler for PL/I"