Perhaps you should try some spelling variations:
thi nghiem » thuc nghiem
hoach thi » hoach thu, hoach toi, hoach thay
nghiem so » nghiem son, nghiep so, nghiem su
sach dao » lanh dao
dao nghe » day nghe, da nghe, dat nghe
tu sach » thu sach, su sach, te sach
nghe d » nghe di, nghe _, nghe 新
so hoc » co hoc, mo hoc, so hoa
d hoc » du hoc, ad hoc, de hoc

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 dao nghe d hoc ) or ( thu hoach thi nghiem so hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach dao nghe d hoc ) OR ( thu hoach thi nghiem so hoc )).
• Adding a wildcard symbol may retrieve word variants: (( tu sach dao nghe d hoc ) or ( thu hoach thi nghiem so hoc ))*.