Perrin, P. G. (1965). Writer's guide and index to english (4th ed.). Chicaco: Scott, Foresman and Company.
Παραπομπή Chicago StylePerrin, Porter G. Writer's Guide and Index to English. 4th ed. Chicaco: Scott, Foresman and Company, 1965.
Παραπομπή MLAPerrin, Porter G. Writer's Guide and Index to English. 4th ed. Chicaco: Scott, Foresman and Company, 1965.
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