Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hanh dai » hanh tai, hanh dao, vanh dai
van hanh » van thanh, ban hanh, van anh
cham hoc » cham soc, chat hoc, cham hoi
hoc van » hoc dan, hoc va, hoc vat
te sach » toc sach
sach ty » sach y, sach tu, sach thu
tang ma » mang may, tang van
nang ma » sang ma, nang cao, mang may
hieu va » hieu qua

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 ty ((nang ma) or (tang ma)) hoa. ((hieu va) OR (lieu va)) cham hoc van hanh dai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty ((nang ma) OR (tang ma)) hoa. ((hieu va) OR (lieu va)) cham hoc van hanh dai cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty ((nang ma) or (tang ma)) hoa. ((hieu va) OR (lieu va)) cham hoc van hanh dai cua triet".
• Adding a wildcard symbol may retrieve word variants: te sach ty ((nang ma) or (tang ma)) hoa. ((hieu va) OR (lieu va)) cham hoc van hanh dai cua triet*.