Chigirinsky, Valeriy, and Olena Naumenko. “Invariant Differential Generalizations in Problems of the Elasticity Theory As Applied to Polar Coordinates”. Eastern-European Journal of Enterprise Technologies 5, no. 7 (107) (October 31, 2020): 56–73. Accessed May 7, 2024. https://journals.uran.ua/eejet/article/view/213476.