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