| Year | 1999 |
| Date | 19-Nov |
| Volume | 183 |
| Issue | 4,107 |
| Page | 628 |
| Category | Optical |
| Part | 1 |
| Title | An Optical Comparator for the Home Workshop |
| Author | Richard E.Butterick (Canada) |
| Notes | Describes the construction. Introduction, applications and specifications, overview |