2. B. Yang, A. Bonfigli, V. Pagani, T. Isohanni, A. Von-Knorring, A. Jutila, V. Judin: “Effect of oral supplementation and topical application of supercritical CO2 extracted sea buckthorn oil on skin ageing of female subjects”, J. Appl. Cosmetol. 27, 13-25 (January/March 2009).