| Authors | Reference Point | Notes |
| Gilchrist and Buxton, 1939 [7] | 2 mm from distal point of lunula | Lunula not clear in 4th and 5thfingers, blurred with magnification |
| Bean, 1953 [9] | Cuticle | Cuticle may be damaged due to hydration, dehydration, friction, manicuring. May be hard to see or absent in some individuals |
| Hillman, 1955 [10] | Convexmargin of lunula | Used calipers to increase accuracy |
| Babcock, 1955 [11] | Lunula | Magnified photographs 6.4x |
| Sibinga, 1959 [12] | Lunula | Magnified photographs 35x |
| Geoghegan et al., 1958 [13] | Lunula | Beck Luminex magnifier |
| Morton, 1962 [14] | Lunula | Drilled holes, magnified photographs |
| Bean, 1963 [15] | Tattoo on proximal nail fold adjacent to cuticle | Magnified photographs |
| Dawber, 1970 [17] | 3 mm from cuticle | 8x magnifier |
| Orentreich, 1979 [19] | Convex margin of lunula | Magnifier |