Ketchum, Paul A.
John Wiley & Sons, 1984
Buku Teks
Bond, John
Churchill Livinstone , 1994
Buku Teks
Barry, Anne-Marie
SAGE Publications Ltd, 2016
Buku Teks
Weis, Gregory L
Prentice Hall, 1996
Buku Teks
Trostle, James A
Cambridge University Press, 2005
Buku Teks