Science Education Center, U. o. t. P. (1972). Environmental science 1: Pupil's guide Part 1 and Part 2 (Revised experimental edition.). Science Education Center, University of the Philippines.
Lua i Stíl Chicago (17ú heag.)Science Education Center, University of the Philippines. Environmental Science 1: Pupil's Guide Part 1 and Part 2. Revised experimental edition. Quezon City: Science Education Center, University of the Philippines, 1972.
Lua MLA (9ú heag.)Science Education Center, University of the Philippines. Environmental Science 1: Pupil's Guide Part 1 and Part 2. Revised experimental edition. Science Education Center, University of the Philippines, 1972.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.