Stride, Chris.
John Wiley & Sons, 2007
Buku Teks
Super, Donald E., author
Harper & Row , 1962
Buku Teks
Cohen, Ronald Jay, author
McGraw-Hill, 2005
Buku Teks
Super, Donald E., author
Harper, 1962
Buku Teks
Papalia, Diane E., author
Academic Internet Publishers, 2007
Buku Teks