McFadden, David
McClelland and Stewart, 1978
Buku Teks
Philip, George, author
George Philip and Son, 1983
Buku Referensi
Amarina Ashar Ariyanto, author
Fakultas Psikologi Universitas Indonesia, 2011
Artikel Jurnal
Aboubaker. Y.Y. Alfakhri, author
Faculty of Engineering, Universitas Indonesia, 2018
Artikel Jurnal
Routledge, 1997.
Buku Teks