Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
thanh tai » thanh hai, thanh toan, doanh tai
ban thanh » ban hanh, ban hang
quoc ban » quoc bao, quoc lan, quoc quan
cac quoc » cac nuoc, cac cuoc, cao quoc
vien cac » vien bach, vien dai, vien da
tai cua » thai cua, tai cuc, tri cua
sach ky » sach y, sach ty, sach kem
cao hoi » cau hoi, cao hoc, tao hoi
cua tre » cua te, cuu tre, cua triet
co hoi » co hoc, co loi
sac ky » cac ky, sai ky

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 ((cao hoi) or (co hoi)). hieu vien cac quoc ban thanh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sac ky)) nang ((cao hoi) OR (co hoi)). hieu vien cac quoc ban thanh tai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) OR (sac ky)) nang ((cao hoi) or (co hoi)). hieu vien cac quoc ban thanh tai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) OR (sac ky)) nang ((cao hoi) or (co hoi)). hieu vien cac quoc ban thanh tai cua tre*.