Perkongsian dengan warga maya
24/01/2016 07:40
Student Repository, University Malaya https://studentsrepo.um.edu.my/5349/24/BIBLIOGRAFI.pdf
Universiti Sains Malaysia https://education.usm.my/images/docs/DigesPendidik/DP2012-2/dp2012-2-01.pdf
National Library Board, Singapore
