Elshafei, A. (1969). Part Period Algorithm. The Institute of National Planning.
Cita Chicago (17th ed.)Elshafei, Alwalid. Part Period Algorithm. Cairo: The Institute of National Planning, 1969.
Cita MLA (9th ed.)Elshafei, Alwalid. Part Period Algorithm. The Institute of National Planning, 1969.
Atenció: Aquestes cites poden no estar 100% correctes.