| year of publication | ISBN | author(s) | title |
|---|---|---|---|
| 1996 | 978-0-9667580-0-9 | Judith G. Rappold | Starting Your Secret Shopping Business |
| 2004 | 978-0-9667580-3-0 | Judith Rappold | Get Paid to Shop: Opportunities in Mystery Shopping |
| 2002 | 978-0-9667580-4-7 | '' | Starting Your Mystery Shopping Business |