1. Gill P, Jeffreys A J, Werrett D J (1985) Nature 318:511
2. Olsen R D (1978) in: Scotts Fingerprint Mechanics. Charles C Thomas, Springfield, Illinois, USA
3. Moenssens A A (1975) in: Fingerprint Techniques. Chilton Book Company, Pennsylvania, USA
4. Cowger J F (1983) in: Friction Ridge Skin. Elsevier, Oxford
5. Weiner J S, Hellmann K (1960) Biol. Rev. 35(2):141