edited by Valerie Kinsella
Cambridge Uniiversity Press , 1979
Buku Teks
Reeves, Tom Kynaston, author
McGraw-Hill, 1981
Buku Teks
Mills, Stephen
Penguin Books, 1986
Buku Teks
George Allen and Unwin, 1982
Buku Teks
Gilani, Ijaz Shafi
Gallup Pakistan, 1985
Buku Teks