Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hieu van » hieu va, thien van, lieu va
doanh va » doan va, doanh cua, hanh va
sach ty » sach y, sach tu, sach thu
tu sach » thu sach, su sach, te sach
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
van cam » van nam, van lam, van cau
cam so » nam so, ham so, cam lo
so van » su van, vo van

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((nang xa) OR (lang xa)) hoi. hieu van cam so van ((doanh va) OR (doanh tai)) cua triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty ((nang xa) or (lang xa)) hoi. hieu van cam so van ((doanh va) OR (doanh tai)) cua triet~".
• Adding a wildcard symbol may retrieve word variants: tu sach ty ((nang xa) or (lang xa)) hoi. hieu van cam so van ((doanh va) OR (doanh tai)) cua triet*.