Cita APA (7th ed.)
Blough, G. O., & Schwartz, J. (1990). Elementary school science and how to teach it (8th ed.). Harcourt brace.
Cita Chicago (17th ed.)
Blough, Glenn O., i Julius Schwartz. Elementary School Science and How to Teach It. 8th ed. Philadelphia: Harcourt brace, 1990.
Cita MLA (9th ed.)
Blough, Glenn O., i Julius Schwartz. Elementary School Science and How to Teach It. 8th ed. Harcourt brace, 1990.
Atenció: Aquestes cites poden no estar 100% correctes.