Science Education Center, U. o. t. P. (1972). Environmental science 1: Pupil's guide Part 2 (Revised experimental ed.). Science Education Center, University of the Philippines.
Παραπομπή σε μορφή Chicago (17η εκδ.)Science Education Center, University of the Philippines. Environmental Science 1: Pupil's Guide Part 2. Revised experimental ed. Quezon City: Science Education Center, University of the Philippines, 1972.
Παραπομπή σε μορφή MLA (9th εκδ.)Science Education Center, University of the Philippines. Environmental Science 1: Pupil's Guide Part 2. Revised experimental ed. Science Education Center, University of the Philippines, 1972.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.