Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
dieu cua » dieu tra
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
hieu ve » hieu va, hieu van
cac luc » cau luc, coc luc, cac nuoc
luc van » luoc van, luu van, duc van
te cua » tue cua, le cua, de cua
te sai » te tai, te bai, te lai
sai ky » sac 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 sai ky ((nang xa) OR (lang xa)) hoi. hieu ve cac luc van hanh ((dieu cua) or (te cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sai ky ((nang xa) OR (lang xa)) hoi. hieu ve cac luc van hanh ((dieu cua) OR (te cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sai ky ((nang xa) OR (lang xa)) hoi. hieu ve cac luc van hanh ((dieu cua) or (te cua)) tre".
• Adding a wildcard symbol may retrieve word variants: te sai ky ((nang xa) OR (lang xa)) hoi. hieu ve cac luc van hanh ((dieu cua) or (te cua)) tre*.