Toumpanis, I.     The contribution of video referral system of objectifying the current hockey umpiring [Текст] / I. Toumpanis, T. Dimitrieska // Olympic Sports and Sport for All. Sport, Stress, Adaptation : proceeding book of XVI International Scientific Congress and VI International Scientific Congress (17-19 May 2012 ) : extra issue of Sport and science / ed. staff: P. Gashev, D. Dasheva, S. Videnova ; National Sport Academy "Vassil Leski". — Sofia, 2012. — P. 798-801.