American Psychological Association, 2018
Majalah, Jurnal, Buletin
Sternberg, Robert J.
Wadsworth and Cengage Learning, 2012
Buku Teks
The British Psychological Society, 2018
Majalah, Jurnal, Buletin
The British Psychological Society, 2018
Majalah, Jurnal, Buletin
The Australian Psychology Society Limited,
Majalah, Jurnal, Buletin