Perhaps you should try some spelling variations:
nghiem su » nghiem xu, nghiem ngu, nghiem dau
thu sach » thuat sach, thuoc sach, thu hoach
dat nghe » day nghe, da nghe, dang nghe
nghe 新 » nghe _
hoach ha » hoach va, hoach hoi, hoach su
tu sach » su sach, te sach, tu cach
新 hoc » y hoc, _ hoc, o hoc
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) or (thu sach)) dat nghe 新 hoc ) or ( thu ((hoach ha) OR (hoach xay)) nghiem su hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( ((tu sach) OR (thu sach)) dat nghe 新 hoc ) OR ( thu ((hoach ha) OR (hoach xay)) nghiem su hoc )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( ((tu sach) or (thu sach)) dat nghe 新 hoc ) or ( thu ((hoach ha) OR (hoach xay)) nghiem su hoc ))".
• Adding a wildcard symbol may retrieve word variants: (( ((tu sach) or (thu sach)) dat nghe 新 hoc ) or ( thu ((hoach ha) OR (hoach xay)) nghiem su hoc ))*.