Perhaps you should try some spelling variations:
trinh nghien » trinh nghe, kinh nghiem, trinh thiet
canh trinh » canh tranh, hanh trinh, canh tinh
tai nghiem » trai nghiem, thi nghiem, trac nghiem
nghiem de » nghiem d, nghiem te, nghiem ve
sach tai » sach bai, sach tham, sach dao
toc canh » luoc canh, ngoc canh, luc canh
te sach » toc sach
de hoc » te hoc, du hoc, dien hoc
h hoc » _ hoc, o hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( te sach tai nghiem de hoc ) or ( toc canh trinh nghien ((h hoc) or (y hoc)) ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( te sach tai nghiem de hoc ) OR ( toc canh trinh nghien ((h hoc) OR (y hoc)) )).
• Adding a wildcard symbol may retrieve word variants: (( te sach tai nghiem de hoc ) or ( toc canh trinh nghien ((h hoc) or (y hoc)) ))*.