?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adissertation&rft.aufirst=Karen+Lissette&rft.aulast=Calder%C3%B3n+Guti%C3%A9rrez&rft.au=Calder%C3%B3n+Guti%C3%A9rrez%2C+Karen+Lissette&rft.tpages=125&rft.inst=Universidad+Nacional+Polit%C3%A9cnica.&rft.degree=%5B%22eprint_fieldopt_thesis_type_bachelor%22+not+defined%5D&rft.title=T%C3%A9+de+Marango.&rft.date=2017