Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
kho tang » cao tang
thai son » thai den, thai do, thai hoc
cua tre » cua te, cuu tre, cua triet
son van » song van, san van, son va
hieu va » hieu qua
ky tang » ky nang, ky dang, ky trong
ha hoi » hoa hoi, ha noi, xa hoi
vi cua » vai cua, di cua
te cac » tu cac, ve cac, te cao

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

• Performing a fuzzy search may retrieve terms with similar spellings: te cac ((ky tang) OR (kho tang)) ha hoi. ((hieu va) or (lieu va)) thai son van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te cac ((ky tang) OR (kho tang)) ha hoi. ((hieu va) OR (lieu va)) thai son van hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te cac ((ky tang) OR (kho tang)) ha hoi. ((hieu va) or (lieu va)) thai son van hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: te cac ((ky tang) OR (kho tang)) ha hoi. ((hieu va) or (lieu va)) thai son van hanh vi cua tre*.