ACUERDO DE RÉGIMEN DE CO-TUTELA DE UNA TESIS DOCTORAL ENTRE LA UNIVERSIDADE DE VIGO Y INSTITUTO NACIONAL DE AGRONOMÍA DE TÚNEZ (UNIVERSIDAD DE CARTAGO) / COOPERATION AGREEMENT FOR THE JOINT SUPERVISION OF A DOCTORAL THESIS BETWEEN THE UNIVERSTIDADE DE VIGO AND THE NATIONAL INSTITUTUE OF AGRONOMY OF TUNISIA (INAT) (CARTHAGE UNIVERSITY)