H. AWANG ; M. N. ATAN ; N. ZAINUL ABIDIN. http://jestec.taylors.edu.my/Vol%2011%20issue%201%20January%202016/Volume%20(11)%20Issue%20(1)%20096-%20108.pdf.
,
2016
H. AWANG ; M. H. AHMAD ; M. Z. Al-MULALI http://jestec.taylors.edu.my/Vol%2010%20issue%204%20April%202015/Volume%20(10)%20Issue%20(4)%20496-%20508.pdf.
,
2015