1. Arcana alphanumerica, or, The secrets of HMD call numbers revealed : being a description of call numbers used for printed materials in the History of Medicine Division, with an explanation of their meaning, usage, and derivation Author(s): Clausen, Carol. Publication: Bethesda : National Library of Medicine, History of Medicine Division, 1992 Subject(s): Book ClassificationLibraries, MedicalUnited StatesNational Library of Medicine (U.S.). History of Medicine Division.