Guba, E. G., & Lincoln, Y. S. (1981). Effective evaluation. Jossey-Bass Publishers.
Lua i Stíl Chicago (17ú heag.)Guba, Egon G., agus Yvonna S. Lincoln. Effective Evaluation. San Francisco: Jossey-Bass Publishers, 1981.
Lua MLA (8ú heag.)Guba, Egon G., agus Yvonna S. Lincoln. Effective Evaluation. Jossey-Bass Publishers, 1981.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.