Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
vien cac » vien bach, vien dai, vien da
hanh vai » hanh vi, hanh tai, hanh van
sach dao » lanh dao
cac tuc » cac toc, cac tu, cac tac
hanh va » hang va, hanh vi
sach lo » sach doi, sach hoi, sach moi
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet
tuc va » thuc va, truc va, tuc xa

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

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