Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
phan trinh » thanh trinh, phan tich, phan thanh
duoc khoi » duoc hoi, buoc khoi, duoc khoa
cuoc khoi » buoc khoi, cuoc doi, quoc hoi
toc hanh » hoc hanh, doc hanh, tuc hanh
hoc phan » hoc dan, hoc pho
trinh o » trinh do, trinh co, trinh mo
o khi » co khi, bo khi

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( toc hanh trinh o khi đong luc ) or ( hoc phan trinh ((duoc khoi) or (cuoc khoi)) đong luc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( toc hanh trinh o khi đong luc ) OR ( hoc phan trinh ((duoc khoi) OR (cuoc khoi)) đong luc )).
• Adding a wildcard symbol may retrieve word variants: (( toc hanh trinh o khi đong luc ) or ( hoc phan trinh ((duoc khoi) or (cuoc khoi)) đong luc ))*.