Obtaining Reprints--The Effects of Self-Addressed Return Labels
http://baywood.metapress.com/link.asp?target=contribution&id=7U17BW1WCF4BUN1K
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  peer-reviewed

Hartley, James
Journal of Technical Writing and Communication
2002

Abstract:

This article compares the response rates for obtaining journal reprints from colleagues when the requests are made using postcards with or without a self-addressed return label. Higher response rates were obtained from the cards with the self-addressed return labels, and more women responded than did men, but these differences were not statistically significant.