Henni Oktaviani
Fakultas Ilmu Pengetahuan dan Budaya Universitas Indonesia, 1999
UI - Skripsi Membership
Tahkur, Ramesh
Westview Press, 1986
Buku Referensi
edited by Gordon Greenwood and Norman Harper
F.W. Cheshire, 1957
Buku Teks
by J. Swiericzuk ... [and others]
Pitman, 1980
Buku Teks
edited by Gordon Greenwood and Norman Harper
F.W. Chesire, 1968
Buku Teks