CAMPOS VALLEJO, Rolando Martin; IBARRA ROSERO, Edison Marcelo. Incidence of covid 19- at the Carchi state polytechnic university before and after the vaccination stage. Tierra Infinita, [S. l.], v. 8, n. 1, p. 189–198, 2022. DOI: 10.32645/26028131.1163. Disponível em: https://www.revistasdigitalesupeceduec35.biteca.online/index.php/tierrainfinita/article/view/1163. Acesso em: 18 dec. 2025.