Eells, Richard
R.D. Irwin, 1969
Buku Teks
Viola, Richard H.
W.B. Saunders Company, 1977
Buku Teks
Atty Kurniawati, author
1998
UI - Skripsi (Membership)
Arrow, Kenneth J., author
John Wiley & Sons, 1951
Buku Teks
Airin Y. Saleh, author
2002
UI - Skripsi (Membership)