Evaluation of Collagen Dermal Filler with Lidocaine for the Correction of Nasolabial Folds: A Randomized, Double-Blind, Multicenter Clinical Trial oleh Yang CY, Chang YC, Tai HC, Liao YH, Huang YH, Hui RCY, Kuo YS, Horng SY, Sheen YS, Chen TM, Tzeng YS, Wang CH, Teng SC, Chang CKO, Chou CY