Prishlyak, O. O. (2003). Topological Classification of <em class="a-plus-plus">m</em&gt;-Fields on Two- and Three-Dimensional Manifolds with Boundary. Ukrains’kyi Matematychnyi Zhurnal, 55(6), 799-805. Retrieved from https://umj.imath.kiev.ua/index.php/umj/article/view/3954