Perhaps you should try some spelling variations:
khanh tra » thanh tra, khanh trach, khanh hoa
sach thi » sach tai, sach thieu, sach tham
sach thu » sach thue, sach thieu, sach tham
nghiem d » nghiem de, nghiem do, nghiem _
tu khanh » vu khanh, tu hanh, tu thanh
tra nghe » thai nghe, va nghe, cua nghe
nghe san » nghe dan, nghe sinh, nghe va
san hoc » van hoc, dan hoc, san ho
d hoc » du hoc, ad hoc, de 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 thi) or (sach thu)) nghiem d hoc ) or ( tu khanh tra nghe san hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu ((sach thi) OR (sach thu)) nghiem d hoc ) OR ( tu khanh tra nghe san hoc )).
• Adding a wildcard symbol may retrieve word variants: (( tu ((sach thi) or (sach thu)) nghiem d hoc ) or ( tu khanh tra nghe san hoc ))*.