Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
cua tre » cua te, cuu tre, cua triet
cau luc » cau truc, cau phuc
hanh de » hanh ve, hanh kem
sach ty » sach y, sach tu, sach thu
nang xa » nang x, lang xa, nang ma
hieu ve » hieu van
luc van » luoc van, luu van, duc van
hieu va » lieu va, hieu qua
de cua » le cua, te cua, dieu cua
sac ky » cac ky, sai ky

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) OR (hieu va)) cau luc van hanh 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) OR (hieu va)) cau luc van hanh 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) OR (hieu va)) cau luc van hanh de cua tre".
• Adding a wildcard symbol may retrieve word variants: te ((sac ky) or (sach ty)) nang xa hoi. ((hieu ve) OR (hieu va)) cau luc van hanh de cua tre*.