Perhaps you should try some spelling variations:
chat triet » chet triet, phat trien, chat thien
thanh lay » thanh lap, thanh tay, thanh lam
thanh ly » thanh ky, thanh le, khanh ly
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
van cac » van cau, van bac, dan cac
nang ho » nang hoc, nang co, tang ho
van hac » van hoc, van ha, van hai
ho hai » hoc hai, pho hai, cho hai

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 ky nang ho hai. hieu ((van cac) or (van hac)) duc va ((thanh ly) OR (thanh lay)) chat triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ho hai. hieu ((van cac) OR (van hac)) duc va ((thanh ly) OR (thanh lay)) chat triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ho hai. hieu ((van cac) or (van hac)) duc va ((thanh ly) OR (thanh lay)) chat triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ho hai. hieu ((van cac) or (van hac)) duc va ((thanh ly) OR (thanh lay)) chat triet*.