Perhaps you should try some spelling variations:
thanh van » thanh san, thanh toan, thanh phan
ban thanh » ban hanh, ban hang
nam duoc » nam thuoc, da duoc, dat duoc
hieu van » hieu va, thien van, lieu va
su sach » so sach, vu sach
van cua » vang cua, ban cua, dan cua
lam duc » lam duoc, pham duc, lam dung
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cuu tre, cua triet
o hai » co hai, so hai, o lai
x hoi » xa hoi, o hoi, x ho

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 ((x hoi) or (o hai)). 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 nang ((x hoi) OR (o hai)). hieu van ((lam duc) OR (nam duoc)) ban thanh van cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang ((x hoi) or (o hai)). hieu van ((lam duc) OR (nam duoc)) ban thanh van cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ((x hoi) or (o hai)). hieu van ((lam duc) OR (nam duoc)) ban thanh van cua tre*.