Earth Science Curriculum Project. (1965). Investigating the earth: Teacher's guide (rev. 1965.). Johnson Publishing.
Cita Chicago (17th ed.)Earth Science Curriculum Project. Investigating the Earth: Teacher's Guide. rev. 1965. Colorado, BO: Johnson Publishing, 1965.
Cita MLA (9th ed.)Earth Science Curriculum Project. Investigating the Earth: Teacher's Guide. rev. 1965. Johnson Publishing, 1965.
Atenció: Aquestes cites poden no estar 100% correctes.