Perhaps you should try some spelling variations:
thai nghiem » thi nghiem, trai nghiem, thai nghien
nghiem duoc » nghiem thuoc, nghe duoc
nghiem dan » nghiem ban, nghiem van, nghiem dau
khac thai » khac trai, khac thi, khach trai
duoc hoc » quoc hoi
phai thi » pham thi, phap thi, hai thi
phan thi » pham thi, tran thi, phan tu
tu khac » vu khac, su khac, ta khac
dan hoc » van hoc, dan toc, dai hoc

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 thai nghiem duoc hoc ) or ( tu ((phai thi) or (phan thi)) nghiem dan hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu khac thai nghiem duoc hoc ) OR ( tu ((phai thi) OR (phan thi)) nghiem dan hoc )).
• Adding a wildcard symbol may retrieve word variants: (( tu khac thai nghiem duoc hoc ) or ( tu ((phai thi) or (phan thi)) nghiem dan hoc ))*.