Perhaps you should try some spelling variations:
thu doanh » thu oanh, tri doanh, thu hoach
va nghiem » van nghiem, va nghien, va nghiep
nghiem su » nghiem xu, nghiem ngu, nghiem dau
sach dao » lanh dao
doanh va » doan va, doanh tai, doanh cua
tu sach » thu sach, su sach, te sach
nghe di » nghe vi, nghe dien, nghe dan
nghe d » nghe 新, nghe 1, nghe 2
su hoc » tu hoc, du hoc, so 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) OR (nghe di))) or (nghe _)) hoc ) or ( thu doanh va nghiem su hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach dao ((((nghe d) OR (nghe di))) OR (nghe _)) hoc ) OR ( thu doanh va nghiem su hoc )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tu sach dao ((((nghe d) OR (nghe di))) or (nghe _)) hoc ) or ( thu doanh va nghiem su hoc ))".
• Adding a wildcard symbol may retrieve word variants: (( tu sach dao ((((nghe d) OR (nghe di))) or (nghe _)) hoc ) or ( thu doanh va nghiem su hoc ))*.