Peterson, P. W. (2005). Changing times changing tenses: A review of the English tenses system. Washington, DC.: United states Department of state.
Παραπομπή Chicago StylePeterson, Patricia Wilcox. Changing Times Changing Tenses: A Review of the English Tenses System. Washington, DC.: United states Department of state, 2005.
Παραπομπή MLAPeterson, Patricia Wilcox. Changing Times Changing Tenses: A Review of the English Tenses System. Washington, DC.: United states Department of state, 2005.
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