Παραπομπή APA

Penna, C. V. (1977). National library and information services: A handbook for planners. Butterworths.

Παραπομπή Chicago Style

Penna, C. V. National Library and Information Services: A Handbook for Planners. London: Butterworths, 1977.

Παραπομπή MLA

Penna, C. V. National Library and Information Services: A Handbook for Planners. Butterworths, 1977.