Perhaps you should try some spelling variations:
khanh trai » khanh tra, khanh trach, thanh tra
khach trai » khac trai, khanh tra, kham trai
nghiem dau » nghiep dau, nghiem va, nghiem ban
sach lang » sach nang, sach quang, cach mang
lang nghe » cong nghe, van nghe
nghe duoc » nghiem duoc, nghe nuoi, che duoc
duoc hoc » quoc hoi
te sach » toc sach
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: (( te sach lang nghe duoc hoc ) or ( tu ((khanh trai) OR (khach trai)) nghiem dau hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( te sach lang nghe duoc hoc ) OR ( tu ((khanh trai) OR (khach trai)) nghiem dau hoc )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( te sach lang nghe duoc hoc ) or ( tu ((khanh trai) OR (khach trai)) nghiem dau hoc ))".
• Adding a wildcard symbol may retrieve word variants: (( te sach lang nghe duoc hoc ) or ( tu ((khanh trai) OR (khach trai)) nghiem dau hoc ))*.