@article{Maksimenko_1998, title={On topological spaces with π<sub class="a-plus-plus">2</sub> = 0}, volume={50}, url={https://umj.imath.kiev.ua/index.php/umj/article/view/4864}, abstractNote={We consider one construction over topological spaces and study its influence on the group π<sub class="a-plus-plus">2</sub&gt;.}, number={8}, journal={Ukrains’kyi Matematychnyi Zhurnal}, author={Maksimenko, S. I.}, year={1998}, month={Aug.}, pages={1144–1146} }