Chang YC, Karlberg AT, Maibach HI PMID: 9455646
Wang MT, Wenger K, Maibach HI PMID: 9455639
Howard R, Frieden IJ, Crawford D, McCalmont T, Levy ML, Rosenblatt DS, Sweetman L, Goodman SI, Ohnstad C, Hart K, Berrios M, Packman S PMID: 9420542