Isi nke 1 na nke 2 nke Freedman, Pisani, and Purves (2007) na-enye a doro anya iwebata n'ime ọdịiche dị n'etiti ndị nwere, na-achịkwa nwere, na enweghị usoro-achịkwa nwere. 
Isi nke 1 na nke 2 nke Freedman, Pisani, and Purves (2007) na-enye a doro anya iwebata n'ime odiiche di n'etiti ndi nwere, na-achikwa nwere, na enweghi usoro-achikwa nwere. 