Elshafei, A. (1969). General Purpose Systems Simulator (GPSS). The Institute of National Planning.
Chicago-viite (17. p.)Elshafei, Alwalid. General Purpose Systems Simulator (GPSS). Cairo: The Institute of National Planning, 1969.
MLA-viite (9. p.)Elshafei, Alwalid. General Purpose Systems Simulator (GPSS). The Institute of National Planning, 1969.
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