McHardy, K.C.; Duguid, K.P.; Jamieson, M.J.; Petrie, J. C.; Towler, H.M.A.
Churchill Livingstone , 1997
Buku Referensi
Genosko, Gary, author
Routledge , 1994
Buku Teks
Holdcroft, David, author
Cambridge University Press, 1991
Buku Teks
Kennedy, Alan, author
St. Martin's Press, 1979
Buku Teks
Jeffrey P. Callen...[et.al.]
W.B. Saunders Company, 1995
Buku Teks