Gaya APA

Guba, E, G., Lincoln, Y, S. (1981). Effective evaluation : improving the usefulness of evaluation results through responsive and naturalistic approaches . San Francisco: Jossey-Bass Pub..

Gaya MLA

Guba, Egon, G., Lincoln, Yuonna, S.. "Effective evaluation : improving the usefulness of evaluation results through responsive and naturalistic approaches". San Francisco: Jossey-Bass Pub., 1981. Text.