Graham, D. A., & Cremers, E. (2002). Robert May (1750-1812) and family: Ironmaster of Elkton, Maryland and Coventry, Chester County, Pennsylvania : a genealogical and biographical sketch : with a short history of Coventry Forge, Chester County, Pennsyvlania. [Ellicott City, Md. (2127 Mt. Hebron Dr., Ellicott City 21042): D.A. Graham].

Graham, Daniel A., and Estelle Cremers. Robert May (1750-1812) and Family: Ironmaster of Elkton, Maryland and Coventry, Chester County, Pennsylvania : A Genealogical and Biographical Sketch : With a Short History of Coventry Forge, Chester County, Pennsyvlania. [Ellicott City, Md. (2127 Mt. Hebron Dr., Ellicott City 21042): D.A. Graham], 2002.

Graham, Daniel A., and Estelle Cremers. Robert May (1750-1812) and Family: Ironmaster of Elkton, Maryland and Coventry, Chester County, Pennsylvania : A Genealogical and Biographical Sketch : With a Short History of Coventry Forge, Chester County, Pennsyvlania. [Ellicott City, Md. (2127 Mt. Hebron Dr., Ellicott City 21042): D.A. Graham], 2002.