Perhaps you should try some spelling variations:
thanh vi » thanh va, thanh ve, nhanh vi
te sach » toc sach
sach ty » sach y, sach tu, sach thu
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
bac so » bac son, bac bo, bac ho
xang x » nang x
x hoi » xa hoi, o hoi, x ho

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 ty xang x hoi. hieu ve ((bac so) OR (bac si)) van ((thanh vi) or (hanh vi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty xang x hoi. hieu ve ((bac so) OR (bac si)) van ((thanh vi) OR (hanh vi)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty xang x hoi. hieu ve ((bac so) OR (bac si)) van ((thanh vi) or (hanh vi)) cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ty xang x hoi. hieu ve ((bac so) OR (bac si)) van ((thanh vi) or (hanh vi)) cua tre*.