Lua APA (7ú heag.)

Elshafei, A. (1968). Product Performance Models PPM. The Institute of National Planning.

Lua i Stíl Chicago (17ú heag.)

Elshafei, Alwalid. Product Performance Models PPM. Cairo: The Institute of National Planning, 1968.

Lua MLA (9ú heag.)

Elshafei, Alwalid. Product Performance Models PPM. The Institute of National Planning, 1968.

Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.