Peterson, P. W. (2005). Changing perspectives: A review of English tense system ( Intermediate/High intermediate). Washington, D.C: United States Department of State.
استشهاد بنمط شيكاغوPeterson, Patricia Wilcox. Changing Perspectives: A Review of English Tense System ( Intermediate/High Intermediate). Washington, D.C: United States Department of State, 2005.
MLA استشهادPeterson, Patricia Wilcox. Changing Perspectives: A Review of English Tense System ( Intermediate/High Intermediate). Washington, D.C: United States Department of State, 2005.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.