Peterson, P. W. (2005). Changing times changing tenses: A review of the English tenses system. Washington, DC.: United states Department of state.
استشهاد بنمط شيكاغوPeterson, Patricia Wilcox. Changing Times Changing Tenses: A Review of the English Tenses System. Washington, DC.: United states Department of state, 2005.
MLA استشهادPeterson, Patricia Wilcox. Changing Times Changing Tenses: A Review of the English Tenses System. Washington, DC.: United states Department of state, 2005.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.