Perhaps you should try some spelling variations:
ban thanh » ban hanh
nam duoc » nam thuoc, da duoc, dat duoc
ban hang » ngan hang
sach ky » sach y, sach ty, sach kem
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky
va nam » van nam, ha nam, va nay
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: tu ((sach ky) or (sac ky)) nang x hoi. lieu va nam duoc ((ban thanh) OR (ban hang)) vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sac ky)) nang x hoi. lieu va nam duoc ((ban thanh) OR (ban hang)) vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) or (sac ky)) nang x hoi. lieu va nam duoc ((ban thanh) OR (ban hang)) vai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sac ky)) nang x hoi. lieu va nam duoc ((ban thanh) OR (ban hang)) vai cua tre*.