Cita APA (7a ed.)

OpenStax (Nonprofit organization), Fraknoi, A. . a., Morrison, D. . a., & Wolff, S. C. a. (2016). Astronomy. OpenStax CNX.

Cita Chicago Style (17a ed.)

OpenStax (Nonprofit organization), Andrew author Fraknoi, David author Morrison, y Sidney C. author Wolff. Astronomy. [Place of publication not identified]: OpenStax CNX, 2016.

Cita MLA (9a ed.)

OpenStax (Nonprofit organization), et al. Astronomy. OpenStax CNX, 2016.