Poptropica English Islands Level 6 Pupil's Book and Online World Access CodeMagdalena Custodio, Oscar Ruiz · First published 2019Open the Tome
Poptropica English Islands Level 5 Teacher's Book with Online World Access Code + Test Book PackMagdalena Custodio, Oscar Ruiz · First published 2018Open the Tome
Poptropica English Islands, Level 5Magdalena Custodio, Oscar Ruiz · First published 2018Open the Tome
Descripción geológica de la Hoja 12c, Laguna Helada, Provincia de CatamarcaOscar J. Ruiz Huidobro · First published 1975Open the Tome
Descripción geológica de la Hoja 7e, SaltaOscar J. Ruiz Huidobro · First published 1968Open the Tome
Constitución y guía territorial del Estado SucreOscar Prieto Ruiz · First published 1964Open the Tome
