Speer, T. (Feb 1997). The give and take of tipping. American
Demographics, 1 of 5. Retrieved July 10, 2003 from ProQuest.umi.com.
Paul, P. (May 2001) The tricky topic of tipping. American Demographics,
1 of 2. Retrieved July 10, 2003 from ProQust.umi.com.
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Hypertext tutorial to teach social science experimental design by Don R. Osborn is licensed under a Creative Commons Attribution 3.0 United States License.
Based on a work at cas.bellarmine.edu.
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