ETL Processing in Business Intelligence Projects for Public Transportation Systems. - Alfredo Cristóbal-Salas; Andrei Tchernykh; Sergio Nesmachnow; Ceila-Yasmin García-Morales; Bardo Santiago-Vicente; José-Eduardo Herrera-Vargas; Carolina Solís-Maldonado; Raúl-Alejandro Luna-Sánchez (ISUM, 2019)