1. The secret of a clear head: bromo caffeine for brain workers Author(s): Keasbey & Mattison Company, author. Publication: Ambler, Penna. : Keasbey & Mattison Company, [between 1881 and 1889?] Subject(s): Headache -- drug therapyFatigue -- drug therapyCaffeine -- therapeutic useHydrobromic Acid -- therapeutic usePhytotherapy