Pandey, B.N., author
Tata McGraw-Hill, 2012
Buku Teks
Macfadyen, A., author
Pitman, 1963
Buku Teks
edited by J.R. Krebs and N.B. Davies
Blackwell, 1995
Buku Teks
Starr, Cecie, author
Brooks/Cole , 2001
Buku Teks
edited by Bernard Stonehouse and Christopher M. Perrins
University Park Press, 1979
Buku Teks