Perhaps you should try some spelling variations:
trinh nghien » trinh nghe, kinh nghiem, trinh thiet
trach nhiem » trac nghiem
sach trinh » sach tranh, hanh trinh, sach kinh
hat trach » sat trach, hai trac
nhiem tu » nhiem thuc, nhiem huu, nghiem su
tuc hat » tuc hai, tu hat, tuc ha
te sach » toc sach
cuu hoc » cua hoc, cuu thuoc, cuu khoa
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: (( tuc hat trach nhiem tu hoc ) or ( te sach trinh nghien cuu hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tuc hat trach nhiem tu hoc ) OR ( te sach trinh nghien cuu hoc ))*.