Castor, C. G. 1., Castor, D. W., & Castor, R. J. (1986). A Castor family in America, or, The descendants of Hans Georg Gerster/John George Castor. [Palm Bay, Fla.]: C.G. Castor.

Castor, Charles G. 1920-, Diana Wike Castor, and Richard J. Castor. A Castor Family in America, Or, The Descendants of Hans Georg Gerster/John George Castor. [Palm Bay, Fla.]: C.G. Castor, 1986.

Castor, Charles G. 1920-, Diana Wike Castor, and Richard J. Castor. A Castor Family in America, Or, The Descendants of Hans Georg Gerster/John George Castor. [Palm Bay, Fla.]: C.G. Castor, 1986.