Perhaps you should try some spelling variations:
nghiem duoc » nghiem thuoc, nghe duoc
canh trinh » canh tranh, hanh trinh, anh trinh
thi nghiem » thuc nghiem
canh tinh » hanh tinh, manh tinh, canh tranh
khach thi » khac thi, khach trai, quach thi
nghien d » nghiem d, nghien o, nghiem de
vu khach » vu khanh, vu khac, vay khach
duoc hoi » quoc hoi, duoc hoc, duoc si
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: (( bo ((canh trinh) OR (canh tinh)) nghien d hoc ) or ( vu khach thi nghiem duoc hoi ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( bo ((canh trinh) OR (canh tinh)) nghien d hoc ) OR ( vu khach thi nghiem duoc hoi )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( bo ((canh trinh) OR (canh tinh)) nghien d hoc ) or ( vu khach thi nghiem duoc hoi ))".
• Adding a wildcard symbol may retrieve word variants: (( bo ((canh trinh) OR (canh tinh)) nghien d hoc ) or ( vu khach thi nghiem duoc hoi ))*.