Perhaps you should try some spelling variations:
trinh nhiet » trinh thiet, trinh nghien, trinh viet
khanh trinh » thanh trinh, nhanh tinh, thanh tinh
hanh trinh » canh tranh, hanh chinh
nhiet tu » nhiet cua, nhin tu, viet tu
nghe duc » nghe duoc, nghe thuc, nghe dung
so hanh » so sanh, so danh, co hanh
nghe du » nghe xu, nghe di, nghe tu
tu hoc » te 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: (( so hanh trinh nhiet tu hoc ) OR ( duy khanh trinh ((nghe du) OR (nghe duc)) hoc ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( so hanh trinh nhiet tu hoc ) or ( duy khanh trinh ((nghe du) OR (nghe duc)) hoc ))~".
• Adding a wildcard symbol may retrieve word variants: (( so hanh trinh nhiet tu hoc ) or ( duy khanh trinh ((nghe du) OR (nghe duc)) hoc ))*.