Lisovskiy, V., V. Derevyanko, ArtushenkoЕ., and V. Yegorenkov. “Stratification of the Positive Column of a DC Discharge in Nitrogen”. East European Journal of Physics, no. 1017(3), Sept. 2012, pp. 95-101, https://periodicals.karazin.ua/eejp/article/view/13708.