Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
cac tuc » cac toc, cac tu, cac tac
va hanh » van hanh, va thanh, va danh
hanh ve » hanh vi, hanh va, hanh kem
tuc va » thuc va, truc va, tuc xa
ve cua » le cua, de cua, te cua

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 ty ((nang ma) or (mang may)) hoi. hieu va cac tuc va hanh ve cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((nang ma) OR (mang may)) hoi. hieu va cac tuc va hanh ve cua triet*.