“Record of Indentures of Individuals Bound Out as Apprentices, Servants, etc., and of German and other Redemptioners in the Office of the Mayor of the City of Philadelphia, October 3, 1771, to October 5, 1773,†The Pennsylvania-German Society Proceedings and Addresses, Vol. XVI (1907): 4, quoting Record of Indentures of Individuals Bound Out as Apprentices, Servants, Etc. in Philadelphia, Pennsylvania by Mayor John Gibson, 1771-72, and Mayor William Fisher, 1773, The American Philosophical Society, Philadelphia, Pennsylvania.