Longman, 1993
Buku Teks
edited by Klaus Gottstein
Campus Verlag , 1992
Buku Teks
Linz, Juan J., author
Johns Hopkins University Press, 1978
Buku Teks
Kitzinger, Uwe W., author
Frederick A. Praeger, 1963
Buku Teks
Gallagher, Michael, author
McGraw-Hill, 2011
Buku Teks