RT Journal Article SR Electronic T1 Topical tretinoin no panacea for photodamaged skin JF Cleveland Clinic Journal of Medicine JO Cleve Clin J Med FD Cleveland Clinic SP 88 OP 89 VO 60 IS 1 A1 Leyden, James J. YR 1993 UL http://www.ccjm.org/content/60/1/88.abstract AB