Cita APA (7a ed.)

(1987). Unobtrusive testing and library reference services / by Peter Hernon and Charles R. McClure.

Cita Chicago Style (17a ed.)

Unobtrusive Testing and Library Reference Services / by Peter Hernon and Charles R. McClure. 1987.

Cita MLA (9a ed.)

Unobtrusive Testing and Library Reference Services / by Peter Hernon and Charles R. McClure. 1987.