https://ignasibeltran.com/2019/04/24/contrato-de-obra-y-servicio-vinculado-a-una-contrata-el-tjue-abre-la-puerta-a-su-calificacion-como-indefinido-casos-c%e2%80%9129-18-c%e2%80%9130-18-y-c%e2%80%9144-18-cobra-servicios-auxilia/