Earth Science Curriculum Project. (1967). Investigating the earth: Earth Science Curriculum Project. Houghton Mifflin.
Chicago Style aipamenaEarth Science Curriculum Project. Investigating the Earth: Earth Science Curriculum Project. New York: Houghton Mifflin, 1967.
MLA aipamenaEarth Science Curriculum Project. Investigating the Earth: Earth Science Curriculum Project. Houghton Mifflin, 1967.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.