Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
mai hoi » mai khoi, dai hoi, lai hoi
hieu va » lieu va, hieu qua
cao tuc » dao tuc, cao duc, cao suc
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
ma hoi » xa hoi, ma hoa, me hoi
va cao » va cac, va co, va dao
tuc va » thuc va, truc va, tuc xa
vi cua » vai cua, di cua

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) or (tu cac)) ky nang ((ma hoi) or (mai hoi)). hieu va cao tuc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (tu cac)) ky nang ((ma hoi) OR (mai hoi)). hieu va cao tuc va hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (tu cac)) ky nang ((ma hoi) or (mai hoi)). hieu va cao tuc va hanh vi cua tre*.