Dyfyniad APA

Rosero Bixby, L. (2008). The exceptionally high life expectancy of Costa Rican nonagenarians.

Dyfyniad Arddull Chicago

Rosero Bixby, Luis. The Exceptionally High Life Expectancy of Costa Rican Nonagenarians. 2008.

Dyfyniad MLA

Rosero Bixby, Luis. The Exceptionally High Life Expectancy of Costa Rican Nonagenarians. 2008.

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.