Imiquimod 5 % cream for the treatment of superficial and nodular basal cell carcinoma: randomized studies comparing low-frequency dosing with and without occlusion. - Sterry,W.; Ruzicka,T.; Herrera,E.; Takwale,A.; Bichel,J.; Andreas,K.; Ding,L.; Thissen,M.R. (Br J Dermatol, 2002)