Naveira, A.M. «On the Total (NonAbsolute) Curvature of a Even Dimensional Submanifold xn Immersed in a R n+2». Revista Matemática Complutense, vol. 7, vol. 7, n.º 2, 1994, p. 279, doi: https://doi.org/10.5209/rev_REMA.1994.v7.n2.17741.