Abraham, Henry J., author
Oxford University Press, 1977
Buku Teks
Bonnicksen, Andrea L
Mayfield Publishing Company, 1982
Buku Teks
Foster, Steve, author
Oxford university press, 2012
Buku Teks
Kalinga Seneviratne, Yeo Lay Hwee
Asia Media Information and Communication centre (AMIC), 2011
Buku Teks
Whipple, Leon
Da Capo Press, 1972
Buku Teks