Perhaps you should try some spelling variations:
hoi nghiem » hoi nhiem, khoi nghiep, thi nghiem
hoach hoi » hoc hoi, hoach ha, sach hoi
thu sach » tu sach, thuat sach, thuoc sach
dao nghe » day nghe, dat nghe, nao nghe
da nghe » day nghe, va nghe, dang nghe
du hoc » tu hoc, duoc hoc
mo hoc » mon hoc, co hoc

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (( thu sach ((dao nghe) OR (da nghe)) ad hoc ) OR ( thu hoach hoi nghiem ((du hoc) OR (mo hoc)) ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( thu sach ((dao nghe) OR (da nghe)) ad hoc ) or ( thu hoach hoi nghiem ((du hoc) or (mo hoc)) ))~".
• Adding a wildcard symbol may retrieve word variants: (( thu sach ((dao nghe) OR (da nghe)) ad hoc ) or ( thu hoach hoi nghiem ((du hoc) or (mo hoc)) ))*.