Walker Sally M. (2010). Early Bird Earth Science Earthquakes. Lerner.
Cita Chicago (17th ed.)Walker Sally M. Early Bird Earth Science Earthquakes. Lerner, 2010.
Cita MLA (9th ed.)Walker Sally M. Early Bird Earth Science Earthquakes. Lerner, 2010.
Atenció: Aquestes cites poden no estar 100% correctes.