Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
vien cac » vien bach, vien dai, vien da
dinh dai » dinh dat, sinh dai, dinh dao
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky
lo va » lo van, lao va, le va

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

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sac ky) or (sai ky)) nang xa hoi. hieu vien cac ((lo va) OR (ly va)) dinh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sac ky) OR (sai ky)) nang xa hoi. hieu vien cac ((lo va) OR (ly va)) dinh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sac ky) or (sai ky)) nang xa hoi. hieu vien cac ((lo va) OR (ly va)) dinh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: te ((sac ky) or (sai ky)) nang xa hoi. hieu vien cac ((lo va) OR (ly va)) dinh dai cua tre*.