| title | ISBN-13 (ISBN-10) | year of publica- tion | other author(s) |
|---|---|---|---|
| The German Element in the Northeast: Pennsylvania, New York, New Jersey & New England | 978-0-8063-5498-9 (0-8063-5498-4) | 2010 | Gustav Koerner · Gustav Philipp K'Orner |
| The German Element in the Ohio Valley: Ohio, Kentucky & Indiana | 978-0-8063-5507-8 (0-8063-5507-7) | 2010 | Gustav Koerner · Gustav Philipp K'Orner |