Brinkerhoff, R. O., & Dressler, D. E. (1990). Productivity measurement: A guide for managers and evaluators. Sage.
Lua i Stíl Chicago (17ú heag.)Brinkerhoff, Robert O., agus Dennis E. Dressler. Productivity Measurement: A Guide for Managers and Evaluators. Newbury Park: Sage, 1990.
Lua MLA (9ú heag.)Brinkerhoff, Robert O., agus Dennis E. Dressler. Productivity Measurement: A Guide for Managers and Evaluators. Sage, 1990.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.