Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
su triet » su viet, su tien, ve triet
sang tai » hang tai, sang tao, tang tai
va triet » va thiet, va trien, ve triet
tp thanh » tap thanh, ta thanh, tu thanh
sach ky » sac ky, sach y, sach ty
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
hieu ve » hieu van
tai hoi » tai khoi, dai hoi, tai hai
ky sang » ky nang, ky dang, ky tang
cam tu » cam thu, nam tu, dam tu
tu tp » tu tu, tu te

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky sang tai hoi. ((hieu ve) OR (hieu va)) cam tu tp thanh dai ((va triet) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky sang tai hoi. ((hieu ve) OR (hieu va)) cam tu tp thanh dai ((va triet) OR (su triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky sang tai hoi. ((hieu ve) OR (hieu va)) cam tu tp thanh dai ((va triet) or (su triet))".
• Adding a wildcard symbol may retrieve word variants: su sach ky sang tai hoi. ((hieu ve) OR (hieu va)) cam tu tp thanh dai ((va triet) or (su triet))*.