Roberts, P. (1970). The Roberts English series: A linguistics program. Harcourt, Brace & World.
Chicago Style aipamenaRoberts, Paul. The Roberts English Series: A Linguistics Program. New York ; Chicago [etc.]: Harcourt, Brace & World, 1970.
MLA aipamenaRoberts, Paul. The Roberts English Series: A Linguistics Program. Harcourt, Brace & World, 1970.
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