Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
tu sach » thu sach, su sach, te sach
cao hoi » cau hoi, co hoi, cao hoc
hieu ve » hieu va, hieu van
cau duc » cao duc, cau luc, chu duc
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, dua tren
y nang » ky nang, ly nang, v nang

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 y nang cao hoi. ((hieu ve) or (lieu va)) cau duc va hanh vi ((cua tre) OR (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang cao hoi. ((hieu ve) OR (lieu va)) cau duc va hanh vi ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang cao hoi. ((hieu ve) or (lieu va)) cau duc va hanh vi ((cua tre) OR (cua triet))".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang cao hoi. ((hieu ve) or (lieu va)) cau duc va hanh vi ((cua tre) OR (cua triet))*.