Babynina Л.С. and Vakhrushev А.А. 2017. Evolution of the Concept “Efficiency”. Vestnik IzhGTU imeni M.T. Kalashnikova. 20, 3 (Oct. 2017), 103–106. DOI:https://doi.org/10.22213/2413-1172-2017-3-103-106.