Perhaps you should try some spelling variations:
khanh thuan » khanh thuong, thanh tuan, khang khuan
nghiem duoc » nghiem thuoc, nghe duoc
nghiem quoc » nghiem nuoc, nghiep quoc, nghiem thuoc
thi nghiem » thuc nghiem
khach thi » khac thi, khach trai, quach thi
khan than » phan than, khoan thanh, khanh thanh

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( vay khach thi nghiem duoc hoc ) or ( van ((khanh thuan) OR (khan than)) nghiem quoc hoi ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( vay khach thi nghiem duoc hoc ) OR ( van ((khanh thuan) OR (khan than)) nghiem quoc hoi )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( vay khach thi nghiem duoc hoc ) or ( van ((khanh thuan) OR (khan than)) nghiem quoc hoi ))".
• Adding a wildcard symbol may retrieve word variants: (( vay khach thi nghiem duoc hoc ) or ( van ((khanh thuan) OR (khan than)) nghiem quoc hoi ))*.