Roden, J., & Zollinger, M. (2010). Zullinger/Zollinger genealogy sequel: Some of the descendants of Jakob Zullinger, German emigrant to Pennsylvania in 1749 with allied families : Keefer, Kell, Over and Shoemaker. Dallas, Texas: JAZ Publishing Company.

Roden, Janice, and Marcel Zollinger. Zullinger/Zollinger Genealogy Sequel: Some of the Descendants of Jakob Zullinger, German Emigrant to Pennsylvania in 1749 With Allied Families : Keefer, Kell, Over and Shoemaker. Dallas, Texas: JAZ Publishing Company, 2010.

Roden, Janice, and Marcel Zollinger. Zullinger/Zollinger Genealogy Sequel: Some of the Descendants of Jakob Zullinger, German Emigrant to Pennsylvania in 1749 With Allied Families : Keefer, Kell, Over and Shoemaker. Dallas, Texas: JAZ Publishing Company, 2010.