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