Buzan, Tony, author
Penguin Books, 1991
Buku Teks
Lorayne, Harry
A Signet Book, 1975
Buku Teks
Novytya Ariyanti, author
2016
UI - Skripsi (Membership)
Foer, Joshua, author
Penguin Books, 2011
Buku Teks
Fakultas Psikologi Universitas Indonesia, 1996
UI - Skripsi (Membership)