Perhaps you should try some spelling variations:
trinh nghien » trinh nghe, kinh nghiem, trinh thiet
sanh trinh » hanh trinh, anh trinh, sinh trinh
sach trinh » sach tranh, hanh trinh, sach kinh
nghien tu » nghiep tu, nghien cuu, nghiep vu
nghien d » nghiem d, nghien o, nghiem de
so sanh » do sanh
vu sach » vu bach, su sach, vu khach
tu hoc » te hoc
d hoc » du hoc, ad 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 trinh nghien tu hoc ) or ( vu sach trinh nghien d hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( so sanh trinh nghien tu hoc ) OR ( vu sach trinh nghien d hoc )).
• Adding a wildcard symbol may retrieve word variants: (( so sanh trinh nghien tu hoc ) or ( vu sach trinh nghien d hoc ))*.