Kathleen McCartnet; Deborah Phillips
Blackwell, 2006
Buku Teks
Santrock, John W., author
McGraw-Hill, 2001
Buku Teks
Nadelman, Lorraine, author
Lawrence Erlbaum, 2004
Buku Teks
Singer, Hans W. (Hans Wolfgang), author
United Nations, 1972
Buku Teks
Smith, Peter K., author
Wiley, 2011
Buku Teks