Walker Sally M. (2010). Early Bird Earth Science Earthquakes. Lerner.
Lua i Stíl Chicago (17ú heag.)Walker Sally M. Early Bird Earth Science Earthquakes. Lerner, 2010.
Lua MLA (9ú heag.)Walker Sally M. Early Bird Earth Science Earthquakes. Lerner, 2010.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.