Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
sach trinh » sach tranh, sach kinh, sac tinh
sach tren » sach tien, sach tranh
trinh tai » trinh toan, trinh tu, trinh han
tai duoc » tao duoc, tan duoc, mai duoc
duoc hoc » quoc hoi
nghe di » nghe vi, nghe dien, nghe dan
di hoc » dai hoc, dia hoc, li hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( te ((sach trinh) or (sach tren)) nghe di hoc ) or ( thuc hanh trinh tai duoc hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( te ((sach trinh) OR (sach tren)) nghe di hoc ) OR ( thuc hanh trinh tai duoc hoc )).
• Adding a wildcard symbol may retrieve word variants: (( te ((sach trinh) or (sach tren)) nghe di hoc ) or ( thuc hanh trinh tai duoc hoc ))*.