Земський, Д. Р., and Д. О. Босий. “The Power Balance of the Dc Traction Substation at the Different Levels of the Voltage Unbalance of the External Power Supply System”. Eastern-European Journal of Enterprise Technologies, vol. 2, no. 8(68), Apr. 2014, pp. 52-57, doi:10.15587/1729-4061.2014.23382.