2Almond- Roesler B,Zouboulis CC. Successful treatment of solor lentigines by brief gentle cryosurgery using aKryomed device. Br J Dermatol,2000,143:216 ~ 218.
3Todd MM, Rallis TM,GerwelsJW,et al.A comparison of 3 lasers and liquid nitrogen in the treament of solar lentigines: a randomized controlled comparative trial. Dermatol,2000, 136:841 ~ 846.