Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
cua viet » ca viet, hoa viet, cua dieu
sach ly » sach y, sach lo, sach hay
sach ty » sach y, sach tu, sach thu
nang co » nang cao, nang doc, nang noi
nam tuc » nam thuc, nam truc, nam tu
va hanh » van hanh, va thanh, va danh
co hoi » co hoc, co loi
tuc va » thuc va, truc va, tuc xa

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 ly) or (sach ty)) nang co hoi. hieu van nam tuc va hanh vi ((cua viet) or (cua vat))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ly) OR (sach ty)) nang co hoi. hieu van nam tuc va hanh vi ((cua viet) OR (cua vat)).
• Adding a wildcard symbol may retrieve word variants: tu ((sach ly) or (sach ty)) nang co hoi. hieu van nam tuc va hanh vi ((cua viet) or (cua vat))*.