Egan, William F.
John Wiley & Sons, 1998
Buku Teks
Universitas Indonesia, 1996
UI - Skripsi (Membership)
Gardner, Floyd M.
John Wiley & Sons, 1979
Buku Teks
Yuddy Syaifudin, author
2011
UI - Skripsi (Open)
Blanchard, Alain
John Wiley & Sons, 1976
Buku Teks