Cita APA (7a ed.)

Duff, L., & Sawdon, P. (2008). Drawing - the purpose. Intellect Books.

Cita Chicago Style (17a ed.)

Duff, Leo, y Phil Sawdon. Drawing - the Purpose. Bristol ; Chicago: Intellect Books, 2008.

Cita MLA (8a ed.)

Duff, Leo, y Phil Sawdon. Drawing - the Purpose. Intellect Books, 2008.