| title | ISBN-13 | year of publica- tion | other author(s) |
|---|---|---|---|
| Vintage American & European Wrist Watch Price Guide: Book 4 | 978-0-913902-58-5 | 1989 | Sherry Ehrhardt · Roy Ehrhardt · Joe Demesy · Peter Planes |
| Vintage American and European Character Wristwatch Price Guide, Book 3 | 978-0-913902-57-8 | 1989 | Sherry Ehrhardt · Roy Ehrhardt · Peter Planes |
| Vintage American and European Wrist Watch Price Guide/Book 2 | 978-0-913902-56-1 | 1988 | Sherry Ehrhardt · Roy Ehrhardt · Joe Demesy · Ken Specht · Peter Planes |
| Vintage American and European Wrist Watch Price Guide/Book 5 | 978-0-913902-59-2 | 1991 | Sherry Ehrhardt · Roy Ehrhardt · Peter Planes |