Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thien van » thi van
thanh vai » thanh hai, thanh van, thanh tai
hieu van » hieu va, lieu va, hieu ve
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
cay cua » ca cua, day cua, cay ca
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, me hoi

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