Pearson, Hesketh
Harper & Brothers, 1954
Buku Teks SO
Weigel, Sigrid
Routledge , 1996
Buku Teks SO
Missac, Pierre, -1986
MIT Press, 1995
Buku Teks SO
Hopkins, Kenneth
The British Council, 1953
Buku Teks SO
M. Martina Triyatna
Fakultas Ilmu Pengetahuan Budaya Universitas Indonesia, 1986
UI - Skripsi Membership