1. L. Zastrow, N. Groth, F. Klein, D. Kockott, J. Lademann and L. Ferrero, IFSCC, 11, 207 (2008).
2. T. Rudolph, P. Buhle, J. Beck, F. Plucker, K.-A. Reiffen and H. Buchlolz, IFSCC, 9, 211 (2006).
3. B.C. Ha, Cosmeceuticals, Shin Kwang Publishing, Seoul (2005).
4. KDA Textbook Editiong Board, Dermatology, 5th Ed., Ryo Mook Gak, Seoul (2008).
5. http://www.khidi.or.kr (2009).