HA, Ku Yong & LEE, Jong Bum. The Nielsen type numbers for maps on a 3-dimensional flat Riemannian manifold. Topological Methods in Nonlinear Analysis [online]. 1 June 2015, T. 45, nr 2, s. 327–362. [accessed 25.3.2023]. DOI 10.12775/TMNA.2015.017.