Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
thuc dan » thuc hanh, hoc dan, thuc vat
cau thuc » cau truc, cuu thuc, can thuc
sach ty » sach y, sach tu, sach thu
hanh va » hang va
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
sai ky » sac ky
va cau » van cau, va cac, va dau

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sach ty) or (sai ky)) nang xa hoi. hieu va cau thuc dan ((hanh va) OR (hanh vi)) cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sai ky)) nang xa hoi. hieu va cau thuc dan ((hanh va) OR (hanh vi)) cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ty) or (sai ky)) nang xa hoi. hieu va cau thuc dan ((hanh va) OR (hanh vi)) cua viet".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) or (sai ky)) nang xa hoi. hieu va cau thuc dan ((hanh va) OR (hanh vi)) cua viet*.