Shah, Amina
Octagon Press, 1975
Buku Teks
Universitas Hasanuddin-SIL, 1984
Buku Teks
Luikham, R.
India, 1983
Buku Teks
edited by Norton Sydney Ginsburg ... [and others]
Prentice-Hall, 1958
Buku Teks
Asia-Pacific Centre of Education for International Understanding
APCEIU. SEAMO, SEAMO INNOTECH, and SEAMO SPAFA, 2010
Buku Referensi