Gaya APA
Heyworth, R, M. (2007).
Science In Focus Chemistry 'O' Level Practical Workbook Teachers Edition .
Singapore:
Pearson Longman.
Gaya MLA
Heyworth, Rex, M.
"Science In Focus Chemistry 'O' Level Practical Workbook Teachers Edition".
Singapore:
Pearson Longman,
2007.
Book.