Tourist Division, Ministry of Transport, Government of India, 1956
Buku Teks
edited by C. Steven LaRue
Fitzroy Dearborn Publishers, 1997
Buku Referensi
Spear, Percival, author
The University of Michigan Press, 1961
Buku Teks
London Murray 1949
Buku Teks
Hobbs, Lisa
McGraw-Hill, 1967
Buku Teks