Chua, Q. N. L. (2007). Why is math so hard?: And many other tips to keeping a sound body and a sound mind. Anvil.
Chicago-referens (17:e uppl.)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.
MLA-referens (9:e uppl.)Chua, Queena N. Lee. Why Is Math so Hard?: And Many Other Tips to Keeping a Sound Body and a Sound Mind. Anvil, 2007.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.