Perhaps you should try some spelling variations:
dang xay » dang van, van xay
truc van » truc va, thuc van, truc ban
hieu ve » hieu va, hieu van
lang xa » lang ha, lang van
hanh ve » hanh vi, hanh va, hanh kem
hanh de » hanh kem
te sac » te sach, te cac, te san
ve cau » ke cau, va cau, ve cac
sac ky » cac ky, sai ky
thiet » thieu

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 ((lang xa) OR (dang xay)) hoi. hieu ve cau truc van ((hanh de) or (hanh ve)) va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky ((lang xa) OR (dang xay)) hoi. hieu ve cau truc van ((hanh de) OR (hanh ve)) va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sac ky ((lang xa) OR (dang xay)) hoi. hieu ve cau truc van ((hanh de) or (hanh ve)) va thiet".
• Adding a wildcard symbol may retrieve word variants: te sac ky ((lang xa) OR (dang xay)) hoi. hieu ve cau truc van ((hanh de) or (hanh ve)) va thiet*.