1. Houpt KR, Cruz PD Jr. Acanthosis nigricans. In : Freedberg IM, Eisen AZ, Wolff K, Austen KF, Goldsmith LA, Katz SI, editors. Fitzpatrick′s Dermatology in General Medicine. 6th edition. New York: McGraw-Hill; 2003. p. 1796-801.
2. Judge MR, McLean WH, Munro CS. Disorders of keratinization. In : Burns T, Breathnach S, Cox N, Griffiths C, editors. Rook′s textbook of dermatology. 7 th ed. Oxford: Blackwell Science Ltd; 2004. p. 34.1-34.111.