Perhaps you should try some spelling variations:
va nghiep » va nghien, lam nghiep, cac nghiep
sach dao » lanh dao
dao nghe » day nghe, da nghe, dat nghe
hoach va » hoach xay, hanh va, doanh va
tu sach » thu sach, su sach, te sach
de hoc » te hoc, du hoc, dien hoc
su hoc » du hoc, so hoc, su ho
tu hoc » te hoc
d hoc » du hoc, ad hoc, y 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 (de hoc)) ) or ( thu hoach va nghiep ((su hoc) OR (tu hoc)) ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach dao nghe ((d hoc) OR (de hoc)) ) OR ( thu hoach va nghiep ((su hoc) OR (tu hoc)) )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tu sach dao nghe ((d hoc) or (de hoc)) ) or ( thu hoach va nghiep ((su hoc) OR (tu hoc)) ))".
• Adding a wildcard symbol may retrieve word variants: (( tu sach dao nghe ((d hoc) or (de hoc)) ) or ( thu hoach va nghiep ((su hoc) OR (tu hoc)) ))*.