Brinkerhoff, R. O., & Dressler, D. E. (1990). Productivity measeurement: :a guide for managers and evaluators. :Sage Publications.
Lua i Stíl Chicago (17ú heag.)Brinkerhoff, Robert O., agus Dennis E. Dressler. Productivity Measeurement: :a Guide for Managers and Evaluators. London: :Sage Publications, 1990.
Lua MLA (8ú heag.)Brinkerhoff, Robert O., agus Dennis E. Dressler. Productivity Measeurement: :a Guide for Managers and Evaluators. :Sage Publications, 1990.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.