Kaufmann, Walter, editor
Reader's Digest Press, 1977
Buku Teks
Kaufmann, William J., (III)
W.H. Freeman and Co. , 1978
Buku Teks
Rian Sabrina Rahmani
Universitas Indonesia, 2018
UI - Skripsi (Membership)
Kaufmann, Elizabeth
Bhuana Ilmu Populer, 1996
Buku Teks
Yakti Rizkinanda
Program Pascasarjana Universitas Indonesia, 2008
UI - Tesis (Open)