Perhaps you should try some spelling variations:
trinh nghien » trinh nghe, kinh nghiem, trinh thiet
khach trai » khac trai, khanh tra, kham trai
canh trinh » canh tranh, hanh trinh, canh tinh
sach trai » sach tai, sach tranh, sach tham
nghiem su » nghiem xu, nghiem ngu, nghiem dau
thu canh » thuc hanh, thu cong, thu ban
nghien d » nghiem d, nghien o, nghiem de
su hoc » tu hoc, du hoc, so 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: (( thuoc ((sach trai) OR (khach trai)) nghiem su hoc ) or ( thu canh trinh nghien d hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( thuoc ((sach trai) OR (khach trai)) nghiem su hoc ) OR ( thu canh trinh nghien d hoc )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( thuoc ((sach trai) OR (khach trai)) nghiem su hoc ) or ( thu canh trinh nghien d hoc ))".
• Adding a wildcard symbol may retrieve word variants: (( thuoc ((sach trai) OR (khach trai)) nghiem su hoc ) or ( thu canh trinh nghien d hoc ))*.