Perhaps you should try some spelling variations:
trinh nghien » trinh nghe, kinh nghiem, trinh thiet
nghiem duoc » nghiem thuoc, nghe duoc
canh trinh » canh tranh, hanh trinh, canh tinh
nghien dan » nghiep dan, nghe dan, nghia dan
sach thi » sach tai, sach thieu, sach tham
sach thu » sach thue, sach thieu, sach tham
duoc hoc » quoc hoi
vu canh » ve canh, vu anh, vu manh
dan hoc » van hoc, dan toc, dai hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( su ((sach thi) OR (sach thu)) nghiem duoc hoc ) or ( vu canh trinh nghien dan hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( su ((sach thi) OR (sach thu)) nghiem duoc hoc ) OR ( vu canh trinh nghien dan hoc )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( su ((sach thi) OR (sach thu)) nghiem duoc hoc ) or ( vu canh trinh nghien dan hoc ))".
• Adding a wildcard symbol may retrieve word variants: (( su ((sach thi) OR (sach thu)) nghiem duoc hoc ) or ( vu canh trinh nghien dan hoc ))*.