[1]
Pontificia Universidad Católica del Ecuador-Santo Domingo (Ecuador)
[2]
U. Técnica Particular de Loja (Ecuador), Experimental Institute for Humanistic, Economic and Social Research (IEXIHES)
[3]
U. Técnica Particular de Loja (Ecuador), Experimental Institute for Humanistic, Economic and Social Research (IEXIHES) / U. de los Andes (Venezuela)