Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
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
tai ky » thai ky, trai ky, sai ky
ve cau » ke cau, va cau, ve cac
cua tu » cua tuc, cua su, cua cu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: te tai ky ((nang xa) or (lang xa)) hoi. hieu ve cau luc van hanh de ((cua te) or (cua tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te tai ky ((nang xa) OR (lang xa)) hoi. hieu ve cau luc van hanh de ((cua te) OR (cua tu)).
• Adding a wildcard symbol may retrieve word variants: te tai ky ((nang xa) or (lang xa)) hoi. hieu ve cau luc van hanh de ((cua te) or (cua tu))*.