Perhaps you should try some spelling variations:
trinh nhiem » trinh nhiet, trinh nghien, trach nhiem
thi nghiem » thuc nghiem
nghiem ad » nghiem d, nghiem ban, nghiem lam
nhiem tu » nhiem thuc, nhiem huu, nghiem su
thu sach » tu sach, thuat sach, thuoc 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 trinh nhiem tu hoc ) or ( ((thu sach) or (te sach)) thi nghiem ad hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( thu cong trinh nhiem tu hoc ) OR ( ((thu sach) OR (te sach)) thi nghiem ad hoc )).
• Adding a wildcard symbol may retrieve word variants: (( thu cong trinh nhiem tu hoc ) or ( ((thu sach) or (te sach)) thi nghiem ad hoc ))*.