Letter from Peter Ruffner in Switzerland to Caleb and Doris Ruffner. He lets them know he has received the research they sent from Mr. Zwicky, and that he would be happy to have them come visit.
Ruffner, Caleb, "Letter to Mr. and Mrs. Caleb Ruffner from Peter Ruffner - April 16, 1985" (1985). Ruffner Family History Records. 32.