Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
ban thanh » ban hang
ban hanh » ban hang
nam mua » nam cua, nam qua, nam xua
vai cua » dai cua, hai cua, lai cua
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
hieu ve » hieu van
nang ma » tang ma, sang ma, nang cao
ma hoi » mai hoi, xa hoi, ma hoa

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

• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang ma hoi. ((hieu ve) OR (hieu va)) nam mua ((ban thanh) OR (ban hanh)) vai cua triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang ma hoi. ((hieu ve) or (hieu va)) nam mua ((ban thanh) OR (ban hanh)) vai cua triet~".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ma hoi. ((hieu ve) or (hieu va)) nam mua ((ban thanh) OR (ban hanh)) vai cua triet*.