Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
luc van » luoc van, luu van, duc van
nang xa » lang xa, nang ma, mang xa
vai cua » dai cua, hai cua, lai cua
doi cua » dai cua, hoi cua, dong cua
hieu ve » hieu va, hieu van
cac luc » cau luc, coc luc, cac nuoc
te sac » te sach, te cac, te san
sac ky » cac ky, sai ky
ve cac » va cac, vien 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 ((nang xa) or (nang x)) hoi. hieu ve cac luc van hanh ((doi cua) or (vai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky ((nang xa) OR (nang x)) hoi. hieu ve cac luc van hanh ((doi cua) OR (vai cua)) tre.
• Adding a wildcard symbol may retrieve word variants: te sac ky ((nang xa) or (nang x)) hoi. hieu ve cac luc van hanh ((doi cua) or (vai cua)) tre*.