edited by Richard Ronald and Marja Elsinga
Routledge, 2012
Buku Teks
edited by Thomas and Dorothy Wilson
Longman, 1991
Buku Teks
Jansson, Bruce S., author
Thompson, 2005
Buku Teks
Trattner, Walter I., author
Free Press, 1984
Buku Teks
Trattner, Walter I., author
Free Press, 1979
Buku Teks