Technical Milestone: The Unified Medical Language System: An Informatics Research Collaboration. - Betsy L. Humphreys; Donald A. B. Lindberg; Harold M. Schoolman; G. Octo Barnett (J. Am. Medical Informatics Assoc., 1998)

Viewpoint: Then and Now and When. - Harold M. Schoolman (J. Am. Medical Informatics Assoc., 1998)