Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
cay thuc » cay thuoc, can thuc, cach thuc
day thuc » dan thuc, dai thuc, dam thuc
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
sach tu » sach thu, cach tu, sach ty
tu nang » tru nang, tu nong, tu nano
nang xa » nang x, lang xa, nang ma
cua tre » cuu tre, cua triet, dua tren
cua te » cua tu

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 tu nang xa hoi. hieu vien ((cay thuc) OR (day thuc)) van hanh vi ((cua tre) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach tu nang xa hoi. hieu vien ((cay thuc) OR (day thuc)) van hanh vi ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach tu nang xa hoi. hieu vien ((cay thuc) OR (day thuc)) van hanh vi ((cua tre) or (cua te))".
• Adding a wildcard symbol may retrieve word variants: su sach tu nang xa hoi. hieu vien ((cay thuc) OR (day thuc)) van hanh vi ((cua tre) or (cua te))*.