APA (7th ed.) Citation

Alvarez, R. C. (2007). Unsolvable problems. Philippines Free Press.

Chicago Style (17th ed.) Citation

Alvarez, Ramiro C. "Unsolvable Problems." Philippines Free Press 2007.

MLA (9th ed.) Citation

Alvarez, Ramiro C. "Unsolvable Problems." Philippines Free Press, 2007.

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