Stephens, R., & Plew, R. (2002). Sams Teach Yourself SQL in 21 Days, Fourth Edition (4th edition.). Sams.
Cita Chicago Style (17a ed.)Stephens, Ryan, y Ronald Plew. Sams Teach Yourself SQL in 21 Days, Fourth Edition. 4th edition. Sams, 2002.
Cita MLA (8a ed.)Stephens, Ryan, y Ronald Plew. Sams Teach Yourself SQL in 21 Days, Fourth Edition. 4th edition. Sams, 2002.
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