Perhaps you should try some spelling variations:
nghiem quoc » nghiem duoc, nghiem nuoc, nghiep quoc
thi nghiem » thuc nghiem
nghiem ad » nghiem d, nghiem ban, nghiem lam
khac thi » khau thi, khuc thi, khuat thi
thai tai » thai tay, thanh tai, thai tran
thap tai » phap tai, tap tai, thanh tai
tu khac » vu khac, su khac, ta 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 thi nghiem ad hoc ) or ( hoa ((thai tai) OR (thap tai)) nghiem quoc hoi ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu khac thi nghiem ad hoc ) OR ( hoa ((thai tai) OR (thap tai)) nghiem quoc hoi )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tu khac thi nghiem ad hoc ) or ( hoa ((thai tai) OR (thap tai)) nghiem quoc hoi ))".
• Adding a wildcard symbol may retrieve word variants: (( tu khac thi nghiem ad hoc ) or ( hoa ((thai tai) OR (thap tai)) nghiem quoc hoi ))*.