Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
truc van » truc va, thuc van, truc ban
cuu tre » cau tren, cau treo
cua tre » cua te, cua triet, dua tren
hanh de » hanh ve, hanh kem
hieu ve » hieu va, hieu van
lang xa » dang xay, lang van
lang ha » long ha
bai ky » ban ky, sai ky, bac ky
ve cau » ke cau, va cau, ve cac
te bai » te bao, te tai, te ban

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

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