McCallum, G. P. (1982). Words people use: Passive/active vocabulary skills for students of English as a second language. New York: Harper & Row.
Chicago-tyylinen lähdeviittausMcCallum, George P. Words People Use: Passive/active Vocabulary Skills for Students of English As a Second Language. New York: Harper & Row, 1982.
MLA-viiteMcCallum, George P. Words People Use: Passive/active Vocabulary Skills for Students of English As a Second Language. New York: Harper & Row, 1982.
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