Perhaps you should try some spelling variations:
sach lang » sach nang, sach quang, cach mang
lang nghe » cong nghe, van nghe
nghe duoc » nghiem duoc, nghe nuoi, che duoc
khanh tra » thanh tra, khanh hoa, thanh tri
nhiem dau » nghiem dau, nhiem mau, nghiep dau
toc sach » hoc sach, doc sach, thuoc sach
duoc hoc » quoc hoi
dau hoc » dai hoc, du hoc, dan hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( toc sach lang nghe duoc hoc ) or ( tu ((khanh trach) or (khanh tra)) nhiem dau hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( toc sach lang nghe duoc hoc ) OR ( tu ((khanh trach) OR (khanh tra)) nhiem dau hoc )).
• Adding a wildcard symbol may retrieve word variants: (( toc sach lang nghe duoc hoc ) or ( tu ((khanh trach) or (khanh tra)) nhiem dau hoc ))*.