Cita APA (7th ed.)

Feldt, R., Johnson, L., & Neumann, M. (2002). Ruby developer's guide. Syngress Pub..

Cita Chicago (17th ed.)

Feldt, Robert, Lyle Johnson, i Michael Neumann. Ruby Developer's Guide. Rockland, MA: Syngress Pub., 2002.

Cita MLA (9th ed.)

Feldt, Robert, et al. Ruby Developer's Guide. Syngress Pub., 2002.