Perhaps you should try some spelling variations:
ky trung » ky trong, ki trung, ly trung
qua tham » qua cham, qua than, qua thanh
soc ban » hoc ban, so ban, soc ba
coc ban » co ban, cac ban, hoc ban
cua tre » cua te, cuu tre, cua triet
te cac » tu cac, ve cac, te cao
ha hoi » hoa hoi, ha noi, xa hoi
vi cua » vai cua, di cua

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 trung ((ha hoi) OR (hoa hoc)). hieu qua tham ((soc ban) OR (coc ban)) hanh vi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te cac ky trung ((ha hoi) or (hoa hoc)). hieu qua tham ((soc ban) OR (coc ban)) hanh vi cua tre~".
• Adding a wildcard symbol may retrieve word variants: te cac ky trung ((ha hoi) or (hoa hoc)). hieu qua tham ((soc ban) OR (coc ban)) hanh vi cua tre*.