APA (7th ed.) Citation

Sia, L. O. (1995). 21st century mathematics. Second year. Phoenix.

Chicago Style (17th ed.) Citation

Sia, Lucy O. 21st Century Mathematics. Second Year. Quezon City: Phoenix, 1995.

MLA (9th ed.) Citation

Sia, Lucy O. 21st Century Mathematics. Second Year. Phoenix, 1995.

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