Perhaps you should try some spelling variations:
trinh nghien » trinh nghe, kinh nghiem, trinh thiet
sanh trinh » hanh trinh, anh trinh, sinh trinh
nghien tu » nghiep tu, nghien cuu, nghiep vu
nghien o » nghiep o, nghiep so, nghiep co
so sanh » do sanh
vu sach » su sach, vu khach
tu hoc » te hoc
o hoc » co hoc, mo hoc, so 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) OR (vu bach)) trinh nghien o hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( so sanh trinh nghien tu hoc ) OR ( ((vu sach) OR (vu bach)) trinh nghien o hoc )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( so sanh trinh nghien tu hoc ) or ( ((vu sach) OR (vu bach)) trinh nghien o hoc ))".
• Adding a wildcard symbol may retrieve word variants: (( so sanh trinh nghien tu hoc ) or ( ((vu sach) OR (vu bach)) trinh nghien o hoc ))*.