Perhaps you should try some spelling variations:
trinh nghien » trinh nghe, kinh nghiem, trinh thiet
nghiem quoc » nghiem duoc, nghiem nuoc, nghiep quoc
canh trinh » canh tranh, hanh trinh, canh tinh
sach trac » sach tranh, sach tham, sach tren
sach truc » cach thuc, sach tren, sach thu
nghien du » nghiep du, nghien cuu, nghiem dau
thu canh » thuc hanh, thu cong, thu ban
du hoc » tu hoc, duoc hoc

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (( thuat ((sach trac) OR (sach truc)) nghiem quoc hoi ) OR ( thu canh trinh nghien du hoc ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( thuat ((sach trac) OR (sach truc)) nghiem quoc hoi ) or ( thu canh trinh nghien du hoc ))~".
• Adding a wildcard symbol may retrieve word variants: (( thuat ((sach trac) OR (sach truc)) nghiem quoc hoi ) or ( thu canh trinh nghien du hoc ))*.