Mohamed Arip, Mohammad Aziz Shah. “Analysis of Validity and Reliability of Survey Self-Assessment Scale-PEER (SPKK-RS) (1 - 22)”.
Jurnal Pendidikan Bitara UPSI, vol. 4, no. 1, May 2019, pp. 1-22,
https://ejournal.upsi.edu.my/index.php/JPB/article/view/2396.