Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
va hanh » van hanh, va thanh, va danh
cam luc » cam xuc, cau luc
hieu va » lieu va, hieu qua
hieu ve » hieu van
tu sach » thu sach, te sach, tu cach
cao hoi » cau hoi, co hoi, cao hoc
ly nang » ky nang, ly hang, ly vang
su sach » so sach, vu sach
luc va » duc va, tuc va, loc va
vi cua » vai cua, di 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) or (su sach)) ly nang cao hoi. ((hieu ve) OR (hieu va)) cam luc va hanh vi cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ly nang cao hoi. ((hieu ve) OR (hieu va)) cam luc va hanh vi cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (su sach)) ly nang cao hoi. ((hieu ve) OR (hieu va)) cam luc va hanh vi cua triet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ly nang cao hoi. ((hieu ve) OR (hieu va)) cam luc va hanh vi cua triet*.