Note 18 — George B. Griffenhagen
Reading edition
E. T. Ellis, "The Story of a Very Old Philadelphia Drug Store," American Journal of Pharmacy, 1908, vol. 75, p. 57; England, op. cit. (footnote 3), pp. 348-350; Parke, Davis & Co., A History of Pharmacy in Pictures, undated booklet edited by George Bender.