Perhaps you should try some spelling variations:
trinh nghien » trinh nghe, trinh thiet, trinh dien
nghiem duoc » nghiem thuoc, nghe duoc
sach trac » sach truc, sach tranh, sach tham
duoc hoc » quoc hoi
thu canh » thuc hanh, thu cong, thu ban
te sach » toc sach
de hoc » te hoc, du hoc, dien 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: (( te sach trac nghiem duoc hoc ) OR ( thu canh ((trinh nghien) OR (kinh nghiem)) de hoc ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( te sach trac nghiem duoc hoc ) or ( thu canh ((trinh nghien) OR (kinh nghiem)) de hoc ))~".
• Adding a wildcard symbol may retrieve word variants: (( te sach trac nghiem duoc hoc ) or ( thu canh ((trinh nghien) OR (kinh nghiem)) de hoc ))*.