William Wiersma. (1991). Research methods in education: An introduction (5th.). Allyn and Bacon.
استشهاد بنمط شيكاغوWilliam Wiersma. Research Methods in Education: An Introduction. 5th. Boston: Allyn and Bacon, 1991.
MLA استشهادWilliam Wiersma. Research Methods in Education: An Introduction. 5th. Allyn and Bacon, 1991.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.