Middleton, Robert Gordon, 1908-
Bombay: D.B. Taraporevala Sons & Private, 1972
Buku Teks
Lenk, John D.
Prentice-Hall, 1983
Buku Referensi
Genn, Robert C.
Parker Publishing Company, 1977
Buku Referensi
Lenk, John D.
McGraw-Hill, 1999
Buku Referensi
Lenk, John D.
McGraw-Hill, 1994
Buku Referensi