Perhaps you should try some spelling variations:
tranh nghiem » trac nghiem, trach nhiem, trinh nghien
trai nghiem » trac nghiem
sanh tranh » canh tranh, sach tranh, lanh tranh
thi nghiem » thuc nghiem
nghiem ye » nghiem de, nghiem te, nghiem ve
so sanh » do sanh
bo sach » co sach, hoc sach
ye hoc » te hoc, de hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( so sanh tranh nghiem ye hoc ) or ( bo sach ((trai nghiem) OR (thi nghiem)) y hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( so sanh tranh nghiem ye hoc ) OR ( bo sach ((trai nghiem) OR (thi nghiem)) y hoc )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( so sanh tranh nghiem ye hoc ) or ( bo sach ((trai nghiem) OR (thi nghiem)) y hoc ))".
• Adding a wildcard symbol may retrieve word variants: (( so sanh tranh nghiem ye hoc ) or ( bo sach ((trai nghiem) OR (thi nghiem)) y hoc ))*.