Wellens, S. J. Houghton Mifflin English grammar and composition. Houghton Mifflin Company.
Čikaški stil citiranja (17. izdanje)Wellens, Sandra J. Houghton Mifflin English Grammar and Composition. Houghton Mifflin Company.
MLA način citiranja (8. izdanje)Wellens, Sandra J. Houghton Mifflin English Grammar and Composition. Houghton Mifflin Company.
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