APA (7th ed.) Citation

De Leon, H. S. (1999). Textbook on the Philippine constitution. Rex Book Store.

Chicago Style (17th ed.) Citation

De Leon, Hector S. Textbook on the Philippine Constitution. Manila: Rex Book Store, 1999.

MLA (9th ed.) Citation

De Leon, Hector S. Textbook on the Philippine Constitution. Rex Book Store, 1999.

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