Curriculum Development Center for Science and mathematics, Science Education Center. (1977). Elementary school science 2: Things change. Department of Education and Culture, Republic of the Philippines.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रCurriculum Development Center for Science and mathematics, Science Education Center. Elementary School Science 2: Things Change. Manila: Department of Education and Culture, Republic of the Philippines, 1977.
एमएलए (9वां संस्करण) प्रशस्ति पत्रCurriculum Development Center for Science and mathematics, Science Education Center. Elementary School Science 2: Things Change. Department of Education and Culture, Republic of the Philippines, 1977.
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