Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
te sach » toc sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
van cau » van dau, van hau, van chat
hanh di » hanh de, hang di, danh di
cua tre » cua te, cuu tre, cua triet
do van » dao van, vo van, so van

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