Graham, Frank Duncan, author
Theodore Audel & Co., 1961
Buku Referensi
Middleton, Robert Gordon, 1908-, author
Bombay: D.B. Taraporevala Sons, 1969
Buku Teks
Anderson, Edwin P., author
D.B. Taraporevala Sons, 1965
Buku Referensi
Dunn, John A., 1949-, author
Routledge, 2009
Buku Teks
Frank, Marcella, author
Prentice-Hall, 1972
Buku Teks