1. James WD, Berger TG, Elston DM. Disturbances of Pigmentation; Pigmented Anomalies of the Extremities. Andrews′ Diseases of the Skin Clinical Dermatology. 11 th ed. China: Elsevier′s; 2006. p. 855-6.
2. Kovarik CL, Spiehogel RL, Kantor GR. Pigmentary Disorders of Skin. In: Lever WF, Elder, Elder DE, editors. Lever′s Text Book of Histopathology. 2 nd ed. New Delhi: Wolters Kluwer; 2009. p. 689-90.
3. AV Anstey. Disorders of Skin Color. In: Burns DA, Breathnach SM, Cox N, Griffith CS, editors. Rook′s Textbook of Dermatology. 8 th ed. Oxford: Wiley Blackwell; 2010. p. 58.20-2.
4. Lapeere H, Boone B, Schepper SD. Hypomelanoses and hypermelanoses. In: Wolff K, Goldsmith LA, Katz S, Gilchrist BA, Paller A, Leffell DJ, editors. Fitzpatrick Dermatology in General Medicine. 7 th ed. New York: McGraw Hill; 2008. p. 631-40.
5. Bolognia JL. Disorders of hypopigmentation and hyperpigmentation. In: Harper J, Orange H, Prose N, editors. Textbook of Pediatric Dermatology. 2 nd ed. United States: Blackwell Science; 2000. p. 868-70.