Cita APA (7a ed.)

Boy, G., & Boy, P. H. (1991). Intelligent assistant systems. Academic Press.

Cita Chicago Style (17a ed.)

Boy, Guy, y Philippa H. Boy. Intelligent Assistant Systems. London [etc.]: Academic Press, 1991.

Cita MLA (9a ed.)

Boy, Guy, y Philippa H. Boy. Intelligent Assistant Systems. Academic Press, 1991.