Cita APA (7a ed.)

Stephens, R. K., & Plew, R. R. (2003). Sams teach yourself SQL in 21 days (4th ed.). SAMS.

Cita Chicago Style (17a ed.)

Stephens, Ryan K., y Ronald R. Plew. Sams Teach Yourself SQL in 21 Days. 4th ed. Indianapolis, Ind.: SAMS, 2003.

Cita MLA (9a ed.)

Stephens, Ryan K., y Ronald R. Plew. Sams Teach Yourself SQL in 21 Days. 4th ed. SAMS, 2003.