Celakoska, Emilija, and Kostadin Trencevski. “Coverings by N-Cubes and the Gauss–Bonnet Theorem”. Annales Fennici Mathematici 43, no. 2 (August 1, 2018): 1063–1072. Accessed November 22, 2024. https://afm.journal.fi/article/view/135773.