Walker Sally M. (2010). Early Bird Earth Science Earthquakes. Lerner.
Chicago-čujuhus (17. p.)Walker Sally M. Early Bird Earth Science Earthquakes. Lerner, 2010.
MLA-čujuhus (9. p.)Walker Sally M. Early Bird Earth Science Earthquakes. Lerner, 2010.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.