Bertrand David · D B · D. Bertrand · David B.
| title | ISBN-13 (ISBN-10) | year of publica- tion | other author(s) |
|---|---|---|---|
| Jak zmienic zycie innych i zarabiac na wlasne | 978-83-88607-20-2 (83-88607-20-0) | ||
| Making a Difference While You're Making a Living | 978-0-9666773-0-0 (0-9666773-0-7) | 1998 | J. Mark Bertrand |