Perhaps you should try some spelling variations:
trinh nghien » trinh nghe, kinh nghiem, trinh thiet
hanh trinh » canh tranh, hanh chinh
hoc hanh » hoc nhanh, hoc thanh, hoc anh
cac trac » cac tac, tap trac, cac tro
nghiem y » nghiep y, nghiem _, nghiem d
hoc cac » hoc cao
_ hoc » _ hon, _ how, _ hop

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( hoc hanh trinh nghien _ hoc ) or ( hoc cac trac nghiem y hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( hoc hanh trinh nghien _ hoc ) OR ( hoc cac trac nghiem y hoc )).
• Adding a wildcard symbol may retrieve word variants: (( hoc hanh trinh nghien _ hoc ) or ( hoc cac trac nghiem y hoc ))*.