Wolfram, Walt, 1941-
American English: dialects and variation
Wiley Balckwell, 2016
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Malmstrom, Jean
Dialects USA
National Council of Teachers of English, 1963
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Discourse-pragmatic variation and change in English: new methods and insights
Heike Pichler, editor
Cambridge University Press, 2016
 Buku Teks SO
Malmstrom, Jean
Dialects USA
National Council of Teachers of English , 1963
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Maguire, Warren
Analysing variation in english
Cambridge University Press, 2011
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