Abbot, Waldo
McGraw-Hill, 1957
Buku Teks
Bender, James F.
Thomas Y. Cornell, 1951
Buku Teks
Coulmas, Florian, author
Blackwell Publishers, 1998
Buku Teks
Andrew Spencer, Arnold M. Zwicky
Blacwell, 2001
Buku Teks
Tourist Division, Ministry of Transport, Government of India, 1956
Buku Teks