Perhaps you should try some spelling variations:
trinh thiet » trinh viet, trinh thi
tai nghiem » trai nghiem, thi nghiem, trac nghiem
nghiem dan » nghiem ban, nghiem van, nghiem dau
thiet dai » thiet hai, thuyet dai, hien dai
toc pham » tac pham, toc cham, toi pham
pham tai » pham thi, pham van
dan hoc » van hoc, dan toc, toan hoc
su sach » vu sach
so sach » so sanh, bo sach, co sach

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( toc pham tai nghiem dan hoc ) or ( ((su sach) OR (so sach)) trinh thiet dai hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( toc pham tai nghiem dan hoc ) OR ( ((su sach) OR (so sach)) trinh thiet dai hoc )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( toc pham tai nghiem dan hoc ) or ( ((su sach) OR (so sach)) trinh thiet dai hoc ))".
• Adding a wildcard symbol may retrieve word variants: (( toc pham tai nghiem dan hoc ) or ( ((su sach) OR (so sach)) trinh thiet dai hoc ))*.