D.  Kuehbeck, Dhar, B. Bijayi, Schoen, E. - M., Cativiela, C., Gotor-Fernandez, V., and Diaz, D. Diaz, ?C-C Bond formation catalyzed by natural gelatin and collagen proteins?, Beilstein Journal of Organic Chemistry, vol. 9, pp. 1111-1118, 2013.