Elshafei, A. (1969). General Purpose Systems Simulator (GPSS). The Institute of National Planning.
Cytowanie według stylu Chicago (wyd. 17)Elshafei, Alwalid. General Purpose Systems Simulator (GPSS). Cairo: The Institute of National Planning, 1969.
Cytowanie według stylu MLA (wyd. 9)Elshafei, Alwalid. General Purpose Systems Simulator (GPSS). The Institute of National Planning, 1969.