Perhaps you should try some spelling variations:
trach nhiem » trac nghiem
trai nghiem » trac nghiem, thi nghiem
nghiem duoc » nghiem thuoc, nghe duoc
cong trach » thong trach, cong tac, cong trinh
nhiem tu » nhiem thuc, nhiem huu, nghiem su
duoc hoc » quoc hoi
su sach » so sach, vu sach
te sach » toc sach
tu hoc » te hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( thu cong trach nhiem tu hoc ) or ( ((su sach) or (te sach)) trai nghiem duoc hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( thu cong trach nhiem tu hoc ) OR ( ((su sach) OR (te sach)) trai nghiem duoc hoc )).
• Adding a wildcard symbol may retrieve word variants: (( thu cong trach nhiem tu hoc ) or ( ((su sach) or (te sach)) trai nghiem duoc hoc ))*.