1. A syllabus of the lectures on hygiene, vital statistics, etc. by Prof. Jno. S. Billings and Dr. A.C. Abbott at the University of Pennsylvania, 1891-92 Author(s): Billings, John S. (John Shaw), 1838-1913, authorAbbott, A. C. (Alexander Crever), 1860-1935, author Publication: Philadelphia : Collins Printing House, 1892 Subject(s): Vital StatisticsBacteriologyEpidemics