The Mystery of the Mixed-Up Mail
| Series | The New Bobbsey Twins |
| Illustrator | David F. Henderson |
| Publisher | Pocket Books |
| Language | English |
| Copyright | 1992 |
| Pages / Font | 84 pages |
| Series Number | 30 |
| ISBN | 0-671-73042-8 |
Added by miketaylor81
| Series | The New Bobbsey Twins |
| Illustrator | David F. Henderson |
| Publisher | Pocket Books |
| Language | English |
| Copyright | 1992 |
| Pages / Font | 84 pages |
| Series Number | 30 |
| ISBN | 0-671-73042-8 |