Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
van hanh » van thanh, ban hanh, van anh
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
hieu ve » hieu van
hieu va » lieu va, hieu qua
cac so » cac co, cac bo, cac ho
so van » su van, vo van
vi cua » vai cua, di cua

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: te sach ky ((nang xa) OR (lang xa)) hoi. ((hieu ve) OR (hieu va)) cac so van hanh vi cua triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky ((nang xa) or (lang xa)) hoi. ((hieu ve) OR (hieu va)) cac so van hanh vi cua triet~".
• Adding a wildcard symbol may retrieve word variants: te sach ky ((nang xa) or (lang xa)) hoi. ((hieu ve) OR (hieu va)) cac so van hanh vi cua triet*.