Chua, Q. N. L. (2007). Why is math so hard?: And many other tips to keeping a sound body and a sound mind. Anvil.
Cita Chicago (17th ed.)Chua, Queena N. Lee. Why Is Math so Hard?: And Many Other Tips to Keeping a Sound Body and a Sound Mind. Pasig City: Anvil, 2007.
Cita MLA (9th ed.)Chua, Queena N. Lee. Why Is Math so Hard?: And Many Other Tips to Keeping a Sound Body and a Sound Mind. Anvil, 2007.
Atenció: Aquestes cites poden no estar 100% correctes.