Perhaps you should try some spelling variations:
ha nghiem » khao nghiem, thi nghiem, thu nghiem
nghiem so » nghiem son, nghiep so, nghiem do
thu sach » thuat sach, thuoc sach, khau sach
dat nghe » day nghe, dang nghe, van nghe
hoach ha » hoach va, hoach xay, hoach hoi
tu sach » su sach, te sach, tu cach
da nghe » day nghe, va nghe, dang nghe
新 hoc » y hoc, _ hoc, o hoc
so hoc » co hoc, mo hoc, so hoa

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 (thu sach)) ((dat nghe) OR (da nghe)) 新 hoc ) or ( thu hoach ha nghiem so hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( ((tu sach) OR (thu sach)) ((dat nghe) OR (da nghe)) 新 hoc ) OR ( thu hoach ha nghiem so hoc ))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( ((tu sach) or (thu sach)) ((dat nghe) OR (da nghe)) 新 hoc ) or ( thu hoach ha nghiem so hoc ))*".