Ancestral Roots and Branches of the Bertkau Family in the United StatesGeoffrey Bertkau, Elizabeth Rapp · First published 2019Open the Tome
Roots, History and Descendants of the Hans Maurbakken Henriksen Family in North AmericaGeoffrey Bertkau, Mary Ellen Atkinson-Bertkau · First published 2022Open the Tome
Roots, History and Descendants of the John Atkinson Family in the United StatesGeoffrey Bertkau, Mary Ellen Atkinson Bertkau · First published 2019Open the Tome
Ancestral Roots and Branches of the Heinrich Reubert Family in the United StatesGeoffrey Bertkau, Nancy Reubert, Martin Reber · First published 2016Open the Tome
