Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
mai hoi » mai khoi, dai hoi, lai hoi
hieu ve » hieu va, hieu van
cau luc » cau truc, cau phuc
luc van » luoc van, luu van, duc van
hanh de » hanh ve, hanh kem
cua tre » cua te, cuu tre, cua triet
te sac » te sach, te cac, te san
sac ky » cac ky, sai ky
ma hoi » xa hoi, ma hoa, me hoi
ve cau » ke cau, va cau, ve cac
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 nang ((ma hoi) or (mai hoi)). hieu ve cau luc van hanh de cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky nang ((ma hoi) OR (mai hoi)). hieu ve cau luc van hanh de cua tre*.