1. [1] A. T. Fomenko, S. V. Matveev. Algorithmic and computer methods for three-manifolds, volume 425 of Mathematics and its Applications. Kluwer Academic Publishers, Dordrecht,
2. 1997, doi: 10.1007/978-94-017-0699-5. Translated from the 1991 Russian original by M. Tsaplina and Michiel Hazewinkel and revised by the authors, With a preface by Hazewinkel.
3. [2] Allen Hatcher. Algebraic topology. Cambridge University Press, Cambridge, 2002.
4. [3] Wolfgang Heil, Víctor Núñez, J. C. Gómez-Larrañaga. Stiefel-Whitney surfaces and the tri-genus of non-orientable 3-manifolds. Manuscripta Math., 100(4):405-422, 1999,
5. doi: 10.1007/s002290050209.