Perhaps you should try some spelling variations:
thanh do » thanh de, thanh pho, thanh hoa
quan tre » quan tren, quan tri, quang tri
hieu va » lieu va, hieu qua
luc ban » cuc ban, luc bat, luc van
duc ban » duc tan, duc van, dua ban
do quan » do quang, dao quan, co quan
su xac » pu xac, su cac
xac ky » cac ky, sac ky, bac ky
nang o » nang co, nang ho, nang ro
va dau » va dao
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: su xac ky nang o hoi. hieu va dau ((luc ban) or (duc ban)) thanh do quan tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su xac ky nang o hoi. hieu va dau ((luc ban) OR (duc ban)) thanh do quan tre.
• Adding a wildcard symbol may retrieve word variants: su xac ky nang o hoi. hieu va dau ((luc ban) or (duc ban)) thanh do quan tre*.