Perhaps you should try some spelling variations:
xay nghiem » xet nghiem, day nghiep, van nghiem
sach dao » lanh dao
dao nghe » day nghe, da nghe, dat nghe
su sach » so sach, vu sach
nghe ad » nghe adn, nghe cad, nghe ar
su pho » sau pho, su ho, su phong
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: (( su sach dao nghe ad hoc ) or ( thu hoach xay nghiem ((((su co) or (su pho))) or (so hoc)) ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( su sach dao nghe ad hoc ) OR ( thu hoach xay nghiem ((((su co) OR (su pho))) OR (so hoc)) )).
• Adding a wildcard symbol may retrieve word variants: (( su sach dao nghe ad hoc ) or ( thu hoach xay nghiem ((((su co) or (su pho))) or (so hoc)) ))*.