Cita APA (7a ed.)

Estes, J. S. ;. J. (1990). Geographic Information Systems An Introduction. Prentice Hall.

Cita Chicago Style (17a ed.)

Estes, Jeffrey Star ; John. Geographic Information Systems An Introduction. Prentice Hall, 1990.

Cita MLA (8a ed.)

Estes, Jeffrey Star ; John. Geographic Information Systems An Introduction. Prentice Hall, 1990.