Altman, Matthew C
John Wiley & Sons, 2014
Buku Teks SO
Korner, S.
Penguin Books, 1955
Buku Teks
edited by Susan Meld Shell, Richard Velkley
Cambridge University Press, 2012
Buku Teks SO
Arief Rahmat Fadhilah
Universitas Indonesia, 2007
UI - Skripsi Membership
Beck, Lewis White
The University of Chicago Press, 1960
Buku Teks SO