Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
sang mai » sang ma, sang tai, lang mai
hieu van » hieu va, thien van, lieu va
thanh vi » hanh vi, thanh va, thanh ve
cau tren » cu tren, dau tren, ca tren
ky sang » ky nang, ky dang, ky tang
mai hoi » mai khoi, dai hoi, lai hoi
van cau » van dau, van hau, van chat
cau cuc » cau cua, cau luc, cau truc
cuc ban » cua ban, cac ban, cuu ban
cuu tre » cua tre, cau treo

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu cac ky sang mai hoi. hieu van cau cuc ban thanh vi ((cuu tre) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cac ky sang mai hoi. hieu van cau cuc ban thanh vi ((cuu tre) OR (cau tren)).
• Adding a wildcard symbol may retrieve word variants: tu cac ky sang mai hoi. hieu van cau cuc ban thanh vi ((cuu tre) or (cau tren))*.