Perhaps you should try some spelling variations:
hieu luat » hieu qua
hieu luc » hieu qua
cham xuc » cam xuc, chat xuc, cham soc
ban hanh » ban hang
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty mang » ty xang, ty hang, tin mang
mang xa » lang xa, mang may, dang xay
cua tre » cua te, cuu tre, cua triet
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 ty mang xa hoi. ((hieu luc) or (hieu luat)) cham xuc ((van ban) or (ban hanh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty mang xa hoi. ((hieu luc) OR (hieu luat)) cham xuc ((van ban) OR (ban hanh)) vi cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ty mang xa hoi. ((hieu luc) or (hieu luat)) cham xuc ((van ban) or (ban hanh)) vi cua tre*.