Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh van » thanh san, thanh toan, thanh phan
hieu van » hieu va, thien van, lieu va
nam duoc » nam thuoc, da duoc, dat duoc
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
ky tang » ky nang, ky dang, kho tang
tang xa » trang xa, tang ma, lang xa
lam duc » lam duoc, pham duc, lam dung
van cua » vang cua, ban cua, dan cua
cua tre » cua te, cuu tre, cua triet

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 tang xa hoi. hieu van ((lam duc) or (nam duoc)) ban thanh van cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky tang xa hoi. hieu van ((lam duc) OR (nam duoc)) ban thanh van cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach ky tang xa hoi. hieu van ((lam duc) or (nam duoc)) ban thanh van cua tre*.