Perhaps you should try some spelling variations:
thuoc ma » hoc ma
hieu van » thien van, lieu va, hieu ve
doan van » doan va, hoang van, luan van
van cua » vang cua, ban cua, dan cua
duoc ma » duoc lam
cua tre » cua te, cuu tre, cua triet
ky lang » ky nang, ky dang, ky tang
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
te cac » tu cac, ve cac, te cao

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 lang xa hoi. ((hieu van) OR (hieu va)) lam ((thuoc ma) OR (duoc ma)) doan van cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te cac ky lang xa hoi. ((hieu van) or (hieu va)) lam ((thuoc ma) OR (duoc ma)) doan van cua tre~".
• Adding a wildcard symbol may retrieve word variants: te cac ky lang xa hoi. ((hieu van) or (hieu va)) lam ((thuoc ma) OR (duoc ma)) doan van cua tre*.