Perhaps you should try some spelling variations:
ban thanh » ban hang
hieu vien » hieu hien, hieu viec, thieu nien
vien dai » hien dai
ban hanh » ban hang
vai cuu » vai cua
dai duc » dao duc, dai dua, mai duc
sach ky » sach y, sach ty, sach kem
cuu tre » cua tre, cau tren, cau treo
sac ky » cac ky, sai ky
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. hieu vien dai duc ((ban thanh) or (ban hanh)) vai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sac ky)) nang x hoi. hieu vien dai duc ((ban thanh) OR (ban hanh)) vai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) OR (sac ky)) nang x hoi. hieu vien dai duc ((ban thanh) or (ban hanh)) vai cuu tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) OR (sac ky)) nang x hoi. hieu vien dai duc ((ban thanh) or (ban hanh)) vai cuu tre*.