Perhaps you should try some spelling variations:
ban thanh » ban hang
ban hanh » ban hang
cau treo » cau theo, cau tren, cau triet
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
van cau » van dau, van hau, van chat
hai cau » hai chau, hai chu, hai hau
ma hoi » mai hoi, xa hoi, ma hoa

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