Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
hieu van » hieu va, thien van, lieu va
va thanh » gia thanh, va tinh, le thanh
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
cua tre » cua te, cuu tre, cua triet
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 truc ((va thanh) or (ban thanh)) va ((cua tre) or (cua vat))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang ma hoi. hieu van cau truc ((va thanh) OR (ban thanh)) va ((cua tre) OR (cua vat)).
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ma hoi. hieu van cau truc ((va thanh) or (ban thanh)) va ((cua tre) or (cua vat))*.