ISBN 978-8491865322
ISBN 978-8491865346
ISBN 978-8411604437
http://recursostic.educacion.es/ciencias/biosfera/web/
WEb geology
https://www.ekigunea.eus/dbh/eu/edukia/dbh1/natura
https://www.ekigunea.eus/dbh/eu/edukia/dbh2/natura
https://www.ekigunea.eus/dbh/eu/edukia/dbh2/natura/nat-2-3?lang=eu
https://ekoetxea.eus/es/urdaibai/
phet.colorado.edu/eu/simulations/browse