(1) Peter C. M. Van de Kerkhof, Marcel C. Pash, Richard K.
(2) Andrew Y. Finlay, Philip Frost, Alex D. Keith, Wallace Snipes – An assessment of factors influencing flexibility of human fingernails – British Journal of Dermatology 1980 – 103, 357-65
(3) R. Baran, D. Schoon – Nail fragility syndrome and its treatment – Journal of Cosmetic Dermatology 2004 – 131-137
(4) Lisa G. Hochman, Richard K. Scher, Mitchell S. Meyerson – Brittle Nails : response to daily biotin supplementation – Therapeutics for the clinician
(5) Victo E. Colombo, Françoise Gerber, Max Bronhofer, George L. Floersheim – Treatment of brittle fingernails and onychoschizia with biotin: scanning electron microscopy – Journal of the American Academy of Dermatology 1990 – 1127-32