1. Observations on the digestive ferments Author(s): Chittenden, R. H. (Russell Henry), 1856-1943 Publication: [Philadelphia? : s.n., 1889?] Subject(s): Digestive System -- enzymology
2. Digestive ferments Publication: [Detroit, Mich.? : Parke, Davis & Co.?, 1889?] Subject(s): Digestive System -- enzymology