Hernández Matos, E., Antonio Andrés M. A., A. Suarez Fernández, C. Nolasco Suarez, F. J. Martínez Martínez, and J. Romero Vázquez. 1991. “Physiographic System Equipped With Liquid Crystal Display”. Revista Mexicana De Ingenieria Biomedica 12 (2):6. http://rmib.com.mx/index.php/rmib/article/view/828.