Cooper, Donald R.
Business research methods
McGraw-Hill, 2006
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Cooper, Donald R.
Business research methods
McGraw-Hill, 2001
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Zikmund, William G.
Business research methods
Dryden Press, 1991
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Zikmund, William G.
Business research methods
Dryden Press, 1988
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Zikmund, William G.
Business research methods
South-Western Cengage Learning, 2013
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