Neuman, William Lawrence, 1950-, author
Pearson Education, 2014
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Creswell, John W., author
Sage, 2014
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Frost, Nollaig, author
McGraw-Hill, 2011
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Neuman, William Lawrence, 1950-, author
Allyn and Bacon, 2003
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Creswell, John W., author
Sage Publication, Inc, 2003
Buku Teks