Perhaps you should try some spelling variations:
nghiem duoc » nghiem thuoc, nghe duoc
thi nghiem » thuc nghiem
tai nghiem » trai nghiem, trac nghiem, thai nghien
nghiem ad » nghiem d, nghiem ban, nghiem lam
hoa thai » hong thai, hoa phan, hoa chat
thai tai » thai tay, thap tai, thanh tai
duoc hoc » quoc hoi
tu khac » su khac, ta khac, tu kham
vu khac » vu kham, vu khanh, bui khac

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( ((tu khac) OR (vu khac)) thi nghiem ad hoc ) or ( hoa thai tai nghiem duoc hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( ((tu khac) OR (vu khac)) thi nghiem ad hoc ) OR ( hoa thai tai nghiem duoc hoc )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( ((tu khac) OR (vu khac)) thi nghiem ad hoc ) or ( hoa thai tai nghiem duoc hoc ))".
• Adding a wildcard symbol may retrieve word variants: (( ((tu khac) OR (vu khac)) thi nghiem ad hoc ) or ( hoa thai tai nghiem duoc hoc ))*.