Sánchez-Larios, H., and S. Guillén-Burguete. “A Theoretical Framework for Modeling Asymmetric, Nonpositive Definite and Nonuniform Distance Functions on R Exp. N”. Journal of Applied Research and Technology, vol. 8, no. 03, Dec. 2010, doi:10.22201/icat.16656423.2010.8.03.466.