Kalalang, I. P. Z. (2011). Kalalang-Ong level of optimism scale. University of the Philippines Diliman Extension Program in Pampanga.
Cita Chicago Style (17a ed.)Kalalang, Irish Pauline Z. Kalalang-Ong Level of Optimism Scale. Pampanga: University of the Philippines Diliman Extension Program in Pampanga, 2011.
Cita MLA (9a ed.)Kalalang, Irish Pauline Z. Kalalang-Ong Level of Optimism Scale. University of the Philippines Diliman Extension Program in Pampanga, 2011.
Precaución: Estas citas no son 100% exactas.