Perhaps you should try some spelling variations:
nghe thuoc » nghe thuc, nghiem thuoc, nghe thuat
thuoc hoc » thuoc ho, thuoc nhom, thuong hoc
khoe nghe » kho nghe
thu sach » thuat sach, thuoc sach, thu hoach
cac van » cac dan
tu sach » te sach, tu cach, vu sach
su sach » so sach, vu sach
nghe tu » nghe thu, nghe xu, nghi tu
su cac » tu cac, su cao, su can
tu hoc » te hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( su cac van nghe thuoc hoc ) or ( ((((tu sach) OR (thu sach))) or (su sach)) khoe nghe tu hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( su cac van nghe thuoc hoc ) OR ( ((((tu sach) OR (thu sach))) OR (su sach)) khoe nghe tu hoc )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( su cac van nghe thuoc hoc ) or ( ((((tu sach) OR (thu sach))) or (su sach)) khoe nghe tu hoc ))".
• Adding a wildcard symbol may retrieve word variants: (( su cac van nghe thuoc hoc ) or ( ((((tu sach) OR (thu sach))) or (su sach)) khoe nghe tu hoc ))*.