Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
vien day » vien dai, vien da, vien xay
day thuc » dan thuc, cay thuc, dai thuc
thuc van » thuc vat, thuc dan, thuc va
van hanh » van thanh, ban hanh, van anh
hanh vai » hanh vi, hanh va, hanh tai
su sach » vu sach
so sach » so sanh, bo sach, co sach
xang xa » lang xa, mang xa, ang xa
vai cua » dai cua, hai cua, lai 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) or (so sach)) ty xang xa hoi. hieu vien day thuc van hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) ty xang xa hoi. hieu vien day thuc van hanh vai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (so sach)) ty xang xa hoi. hieu vien day thuc van hanh vai cua tre*.