C. A. R. Hoare Ian J. Hayes Jifeng He Carroll Morgan A. W. Roscoe Jeff W. Sanders Ib Holm Sørensen J. Michael Spivey Bernard Sufrin 672-686 1987 30 Commun. ACM 8 db/journals/cacm/cacm30.html#HoareHJMRSSSS87 http://doi.acm.org/10.1145/27651.27653 Corrigendum: CACM 30(9): 770 (1987)