1. Manual de dermatología;Conejo-Mir;Aula Médica,2010
2. Hyperkeratosis in response to mechanical irritation;Rubin;J Invest Dermatol.,1949
3. The foot: pathology, aetiology, semiology, clinical investigation and therapy;Regnauld,1986
4. Common causes of pain;Klenerman,1991
5. Skin and subcutaneous tissues;Whiting,1993