Yuri Kalnishkan Volodya Vovk Michael V. Vyugin Loss functions, complexities, and the Legendre transformation. 195-207 2004 313 Theor. Comput. Sci. 2 http://dx.doi.org/10.1016/j.tcs.2003.11.005 db/journals/tcs/tcs313.html#KalnishkanVV04