Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
hieu van » hieu va, thien van, lieu va
doanh va » doan va, doanh tai, doanh cua
va doanh » van doanh, vay doanh, va danh
cua tre » cua te, cuu tre, cua triet
cac che » cac he, cac chien, cac chat
tu sach » thu sach, su sach, te sach
van cac » van hac, van cau, van bac
nang xa » lang xa, nang ma, mang xa

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach y ((nang xa) OR (nang x)) hoi. hieu van cac che va doanh va ((cua tre) or (va triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y ((nang xa) OR (nang x)) hoi. hieu van cac che va doanh va ((cua tre) OR (va triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y ((nang xa) OR (nang x)) hoi. hieu van cac che va doanh va ((cua tre) or (va triet))".
• Adding a wildcard symbol may retrieve word variants: tu sach y ((nang xa) OR (nang x)) hoi. hieu van cac che va doanh va ((cua tre) or (va triet))*.