Perhaps you should try some spelling variations:
khanh trai » khanh tra, khach trai, khanh trach
thu nghiem » thuc nghiem, thi nghiem
nghiem _u » nghiem su, nghiem ngu, nghiem dau
nghiem xu » nghiem su, nghiem xuan, nghiem ngu
vu khanh » vu thanh, van khanh, duy khanh
sach thu » sach thue, sach thieu, sach tham
so sach » so sanh, bo sach, co sach

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( vu khanh trai ((nghiem _u) or (nghiem xu)) hoc ) or ( so sach thu nghiem _ hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( vu khanh trai ((nghiem _u) OR (nghiem xu)) hoc ) OR ( so sach thu nghiem _ hoc )).
• Adding a wildcard symbol may retrieve word variants: (( vu khanh trai ((nghiem _u) or (nghiem xu)) hoc ) or ( so sach thu nghiem _ hoc ))*.