Perhaps you should try some spelling variations:
kho tang » cao tang
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
ky tang » ky nang, ky dang, ky trong
van anh » van thanh, tuan anh, van minh
hoi cua » hoi chuc
cua tre » cua te, cuu tre, cua triet
su cac » tu cac, su cao, su can

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

• Performing a fuzzy search may retrieve terms with similar spellings: su cac ((ky tang) or (kho tang)) xa hoi. hieu van nam thuc ((van anh) or (ngan hang)) hoi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su cac ((ky tang) OR (kho tang)) xa hoi. hieu van nam thuc ((van anh) OR (ngan hang)) hoi cua tre.
• Adding a wildcard symbol may retrieve word variants: su cac ((ky tang) or (kho tang)) xa hoi. hieu van nam thuc ((van anh) or (ngan hang)) hoi cua tre*.