Jan H. P. Eloff The development of a specification language for a computer security system. 143-147 1985 4 Comput. Secur. 2 https://doi.org/10.1016/0167-4048(85)90019-7 https://www.wikidata.org/entity/Q115126527 db/journals/compsec/compsec4.html#Eloff85