Cita APA (7a ed.)

Sidman, J., & Krommes, B. (2011). Swirl by swirl: Spirals in nature. Houghton Mifflin Harcourt.

Cita Chicago Style (17a ed.)

Sidman, Joyce, y Beth Krommes. Swirl by Swirl: Spirals in Nature. Boston: Houghton Mifflin Harcourt, 2011.

Cita MLA (8a ed.)

Sidman, Joyce, y Beth Krommes. Swirl by Swirl: Spirals in Nature. Houghton Mifflin Harcourt, 2011.

Precaución: Estas citas no son 100% exactas.