Gaya APA
Wah, L, E. et al (2010).
'O'level chemistry workout : structured and free-response questions .
Singapore:
Pearson Longman.
Gaya MLA
Wah, Lim, Eng. et al.
"'O'level chemistry workout : structured and free-response questions".
Singapore:
Pearson Longman,
2010.
Text.