o Clyde L. Groff, "English Translation of Pennsylvania Letter 2284 from the Amsterdam Archive" (On file at Lancaster Mennonite Historical Society, No date, viewed 2010 May 12). Translated from records of the [an error occurred while processing this directive] on file at Amsterdam City Archives.
o George Frederick Newman and Clyde L. Groff, Letters From Our Palatine Ancestors 1644-1689, Ann Louise Newman (ed.) (Hershey, PA: G. T. Hawbaker, 1984).
o Clyde L. Groff, Walter B. Groff, Jane Evans Best, The Groff Book, Volume I: A Good Life in a New Land (Ronks, PA: Groff History Associates, 1985). Excerpts localhost/family/peo...pubs/1985/GB/hs.html (2008 Apr 22).
o Jane Evans Best, The Groff Book, Volume II: A Continuing Saga (Ronks, PA: Groff History Associates, 1997). Excerpts localhost/family/peo...pubs/1997/GB/hs.html (2008 Jan 25).