Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
day thuc » dan thuc, dai thuc, dam thuc
cay thuc » cay thuoc, can thuc, cach thuc
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
xang xa » lang xa, mang xa, ang xa
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di cua

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 ty xang xa hoi. hieu vien ((day thuc) or (cay thuc)) van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty xang xa hoi. hieu vien ((day thuc) OR (cay thuc)) van hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach ty xang xa hoi. hieu vien ((day thuc) or (cay thuc)) van hanh vi cua tre*.