Perhaps you should try some spelling variations:
than soc » than hoc, than so, thanh son
cua tre » cua te, cuu tre, cua triet
tang ha » lang ha, tang ma, trung ha
hang di » hang doi, hang dien, hang dich
ky tang » ky nang, ky dang, kho tang
hang vi » hang va, hanh vi, khang voi
te cac » tu cac, ve cac, te cao
ha hoi » hoa hoi, ha noi, xa hoi

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

• If you are trying to use Boolean operators, they must be ALL CAPS: te cac ky tang ha hoi. hieu qua ((than soc) OR (than doc)) ban ((hang vi) OR (hang di)) cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te cac ky tang ha hoi. hieu qua ((than soc) or (than doc)) ban ((hang vi) OR (hang di)) cua tre~".
• Adding a wildcard symbol may retrieve word variants: te cac ky tang ha hoi. hieu qua ((than soc) or (than doc)) ban ((hang vi) OR (hang di)) cua tre*.