Galle, J., & Warren, P. (1989). Ecology discovery activities kit: A complete teaching unit for grades 4-8. Center for Applied Research in Education.
Čikaški stil citiranja (17. izdanje)Galle, Janet, i Patricia Warren. Ecology Discovery Activities Kit: A Complete Teaching Unit for Grades 4-8. West Nyack, N.Y: Center for Applied Research in Education, 1989.
MLA način citiranja (9. izdanje)Galle, Janet, i Patricia Warren. Ecology Discovery Activities Kit: A Complete Teaching Unit for Grades 4-8. Center for Applied Research in Education, 1989.
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