Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
cau treo » cau theo, cau tren, cau triet
vien cac » vien bach, vien dai, vien da
cuu tre » cua tre, cau tren
sach ky » sac ky, sach y, sach ty
nang o » nang co, nang ho, nang ro
va dao » ca dao
dao vi » dao voi, dao ve, dao va
cac su » cach su, cac sau, cac du
o hoi » co hoi, o hoc, o hai
su va » su van, tu va

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 (cac ky)) nang o hoi. hieu vien cac su va dao vi ((cuu tre) OR (cau treo))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (cac ky)) nang o hoi. hieu vien cac su va dao vi ((cuu tre) OR (cau treo))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) or (cac ky)) nang o hoi. hieu vien cac su va dao vi ((cuu tre) OR (cau treo))*".