Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
tu sach » thu sach, te sach, tu cach
su sach » so sach, vu sach
bach tu » bach thu, cach tu, bac tu
cua tre » cuu tre, cua triet, dua tren
ca dan » cac dan, ca dao
dan vi » doan vi, don vi, dan va
cua te » cua tu
x hoi » xa hoi, o hoi, x ho
tu ca » tu cac, tu cua, tu can

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