APA (7th ed.) Citation

System publishing house Pte.Ltd. Activity books. 2. System publishing house Pte.Ltd.

Chicago Style (17th ed.) Citation

System publishing house Pte.Ltd. Activity Books. 2. Singapore: System publishing house Pte.Ltd.

MLA (9th ed.) Citation

System publishing house Pte.Ltd. Activity Books. 2. System publishing house Pte.Ltd.

Warning: These citations may not always be 100% accurate.