@article {2101.05802, archivePrefix = {arXiv}, eprint = {2101.05802}, primaryClass = {gr-qc}, author = {Jerzy Lewandowski and Maciej Ossowski}, title = {Non-singular extension of the Kerr-NUT-(anti) de Sitter spacetimes}, year = {2021}, url = {http://arxiv.org/abs/2101.05802} }