) (2004) "Anopla ("Anoplans")" "Grzimek's Animal Life Encyclopedia: Volume 1 - Lower Metazoans and Lesser Deuterostomes" (2nd ed.
) (2004) "Anopla ("Anoplans")" "Grzimek's Animal Life Encyclopedia: Volume 1 - Lower Metazoans and Lesser Deuterostomes" (2nd ed.