Artikel Jurnal
Mahoney, Bere, author
Learning Matters, 2011
Buku Teks
Haslam, Nick, 1963-, author
SAGE Publications, 2017
Buku Teks
edited by Anthony Gale, Michael W. Eysenck
John Wiley & Sons, 1992
Buku Referensi
Bjorklund, David F., author
2000
Buku Teks