Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
te sach » toc sach
nang xa » nang x, nang ma, mang xa
cua tre » cuu tre, cua triet, dua tren
lang xa » lang ha, dang xay, lang van
hieu ve » hieu va, hieu van
sach ky » sac ky, sach y, sach ty
hanh di » hanh vi, hanh de, hang di
ve cam » ve cham, ve cac, va cam
cua te » cua tu
o van » vo van, so van, do van
cam o » cham o, cam lo, ca o

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky ((nang xa) or (lang xa)) hoi. hieu ve cam o van hanh di ((cua tre) OR (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky ((nang xa) OR (lang xa)) hoi. hieu ve cam o van hanh di ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky ((nang xa) or (lang xa)) hoi. hieu ve cam o van hanh di ((cua tre) OR (cua te))".
• Adding a wildcard symbol may retrieve word variants: te sach ky ((nang xa) or (lang xa)) hoi. hieu ve cam o van hanh di ((cua tre) OR (cua te))*.