Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
hieu va » lieu va, hieu qua
hanh de » hanh ve, hanh kem
luu van » cuu van, luan van, luu hanh
cau luu » cau luc
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky
ma hoi » mai hoi, xa hoi, me hoi
va cau » van cau, va cac, va dau
de cua » le cua, te cua, dieu cua

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