Perhaps you should try some spelling variations:
luu hanh » huu han
thanh de » hanh de, thanh ve, thanh do
cua tre » cua te, cuu tre, cua triet
sach ty » sach y, sach tu, sach thu
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
luu van » cuu van, luan van
de cua » le cua, te cua, dieu cua
sac ky » cac ky, sai ky
ve cau » ke cau, va cau, ve cac

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 (sach ty)) nang xa hoi. hieu ve cau ((luu van) OR (luu hanh)) thanh de cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sac ky) OR (sach ty)) nang xa hoi. hieu ve cau ((luu van) OR (luu hanh)) thanh de cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sac ky) or (sach ty)) nang xa hoi. hieu ve cau ((luu van) OR (luu hanh)) thanh de cua tre*".