Cita APA (7a ed.)

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

Cita Chicago Style (17a ed.)

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

Cita MLA (9a ed.)

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