Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
toc sach » hoc sach, doc sach, thuoc sach
hanh vai » hanh vi, hanh tai, hanh van
hanh va » hang va, hanh vi
cac tuc » cac toc, cac tu, cac tac
van cac » van hac, van cau, van bac
nang xa » nang x, lang xa, nang ma
lo nang » ho nang, ly nang, loai nang
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) OR (toc sach)) lo nang xa hoi. hieu van 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) OR (toc sach)) lo nang xa hoi. hieu van 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) OR (toc sach)) lo nang xa hoi. hieu van cac tuc va ((hanh vai) or (hanh va)) cua tre".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) lo nang xa hoi. hieu van cac tuc va ((hanh vai) or (hanh va)) cua tre*.