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Bopp, Richard E.; Smith, Linda C., eds. (1991). Reference and Information Services: An Introduction. Libraries Unlimited. pp. 309–310. ISBN0-87287-788-4. OCLC23383904.
Wick, Robert L.; Mood, Terry Ann, eds. (1998). ARBA Guide to Biographical Resources, 1986–1997. Libraries Unlimited. p. 229. ISBN0-585-13333-6. OCLC44959776.