Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
van hanh » van thanh, ban hanh, van anh
hieu cua » hieu qua, dieu cua, bieu cua
sach ty » sach y, sach thu, xach tay
hanh di » hanh vi, hanh de, hang di
sach tu » sach thu, cach tu, sach uu
ma hoi » mai hoi, xa hoi, me hoi
du van » duy van, duc van, tu van
di cua » dai cua, doi cua, de cua

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