1. For example, D. J. de SOLLA PRICE, Citation Measures of Hard Science, Soft Science, Technology and Nonscience, in:Communication Among Scientists and Engineers, C. E. NELSON, D. K. POLLACK (Eds), Lexington, Mass.: D. C. Heath, 1970, p. 3–22; H. A. ZCKERMAN, Nobel Laureates in Science: Patterns of Productivity, Collaboration and Authorships,American Sociological Review, 32 (1967) 391–403; and many others.
2. D. de B. BEAVER, R. ROSEN, Collaboration in Science: Response to Professionalism. Unpublished, undated draft kindly provided by Prof. BEAVER in 1975, Williams College.
3. W. HIRSCH, J. F. SINGLETON, Research Support, Multiple Authorship, and Publications in Sociological Journals, 1936–1964. Unpublished paper, Purdue University, 1964. (The present paper has been considerably influenced by the HIRSCH and SINGLETON paper.)
4. N. PATEL, Collaboration in the Professional Growth of American Sociology,Social Science Information, 12 (1973) 77–92.
5. I wish to thank the referee for reminding me of this important distinction.