Nadelman, Lorraine, author
Lawrence Erlbaum, 2004
Buku Teks
Keenan, Thomas, author
Sage Publications, 2004
Buku Teks
Hurlock, Elizabeth Bergner, 1898-, author
McGraw-Hill Kogakusha, 1972
Buku Teks
Maier, Henry W
Harper and Row, 1978
Buku Teks
Gesell, Arnold, author
Harper & Row, 1949
Buku Teks