Perhaps you should try some spelling variations:
nghiem duoc » nghiem thuoc, nghe duoc
va nghiem » van nghiem, va nghien, va nghiep
toc sach » hoc sach, doc sach, thuoc sach
dao nghe » day nghe, da nghe, dat nghe
hoach va » hoach xay, hanh va, doanh va
duoc hoc » quoc hoi
nghe d » nghe di, nghe _, nghe 新
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: (( ((te sach) OR (toc sach)) dao nghe d hoc ) or ( thu hoach va nghiem duoc hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( ((te sach) OR (toc sach)) dao nghe d hoc ) OR ( thu hoach va nghiem duoc hoc )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( ((te sach) OR (toc sach)) dao nghe d hoc ) or ( thu hoach va nghiem duoc hoc ))".
• Adding a wildcard symbol may retrieve word variants: (( ((te sach) OR (toc sach)) dao nghe d hoc ) or ( thu hoach va nghiem duoc hoc ))*.