Science Education Center University of the Philippines. (1972). Environmental science 1 : pupil's guide part 2: Student's text (Revised experimental edition.). Science Education Center University of the Philippines.
Chicago-referens (17:e uppl.)Science Education Center University of the Philippines. Environmental Science 1 : Pupil's Guide Part 2: Student's Text. Revised experimental edition. Quezon City: Science Education Center University of the Philippines, 1972.
MLA-referens (9:e uppl.)Science Education Center University of the Philippines. Environmental Science 1 : Pupil's Guide Part 2: Student's Text. Revised experimental edition. Science Education Center University of the Philippines, 1972.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.