Perhaps you should try some spelling variations:
thieu nien » thien nhien
hieu vien » hieu hien, hieu viec, hieu tieng
hang tai » hang va, dung tai
hoc can » hoc dan, hoc cao, hoc cac
duc van » duc va, duc tan, duc manh
cua tre » cua te, cuu tre, cua triet
tai hoi » tai khoi, dai hoi, tai hai
ly hang » ly quang
sac ly » sac ky
vi cua » vai cua, di cua
te sac » te sach, te cac, te san

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 sac ly hang tai hoi. ((hieu vien) OR (thieu nien)) cac ((duc van) OR (hoc can)) hanh vi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sac ly hang tai hoi. ((hieu vien) OR (thieu nien)) cac ((duc van) or (hoc can)) hanh vi cua tre~".
• Adding a wildcard symbol may retrieve word variants: te sac ly hang tai hoi. ((hieu vien) OR (thieu nien)) cac ((duc van) or (hoc can)) hanh vi cua tre*.