1. Size matters
2. 3 CM Lawrence, and NH Cox . Physical Signs in Dermatology , 2nd edn . London: Mosby, 2002 ; 3 .
3. 4 GH Percival . An Introduction to Dermatology , 11th edn . Edinburgh: E. & S.Livingstone Ltd; 1947 : 11 -12 .
4. 5 RW McKenna . Diseases of the Skin. London: Bailliere, Tindall and Cox, 1923 ; 7 .