ECORFAN Journal-Republic of El Salvador, Volume 5, Number 9, December-2019, is a biannual Journal edited by ECORFAN-Republic of El Salvador. Av. San Quentin, Apartment R 1-17, Col Miralvalle, San Salvador, Republic of El Salvador. http://www.ecorfan.org/republicofelsalvador/journal_issues.php, journal@ecorfan.org. Responsible editor Gilberto Alas Sola. ISSN: 2414-4886. Responsible for the last update of this issue ECORFAN Computer Unit. Imelda Escamilla Bouchán, PhD. Vladimir Luna Soto, PhD. Av. San Quentin, Apartment R 1-17, Col Miralvalle, San Salvador, Republic of El Salvador. Date of last update December 31, 2019. The opinions expressed by the authors do not necessarily reflect the position of the publisher of the publication. It is strictly forbidden the total or partial reproduction of the contents and images of the publication without prior authorization from the National Registry Center of the Republic of El Salvador