Cita APA (7a ed.)

Ullman, J. D., & Widom, J. (1997). A first course in database systems. Prentice-Hall PTR.

Cita Chicago Style (17a ed.)

Ullman, Jeffrey D., y Jennifer Widom. A First Course in Database Systems. Upper Saddle River, New Jersey: Prentice-Hall PTR, 1997.

Cita MLA (9a ed.)

Ullman, Jeffrey D., y Jennifer Widom. A First Course in Database Systems. Prentice-Hall PTR, 1997.