Perhaps you should try some spelling variations:
trinh han » trinh quan
hieu soat » hieu suat, hieu hoat, hieu luat
dung lang » dung dang, dung land, dung quang
dung nang » dun nang, dung dang, dung quang
kien soat » kiem soat, bien soan, kien hoa
han hang » hang hang, han chang, ban hang
van kien » van tien, van hien, van chien
va hieu » van hieu, va dieu, va hien

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( trinh han hang va hieu soat ) or ( tin ((dung lang) OR (dung nang)) van kien soat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( trinh han hang va hieu soat ) OR ( tin ((dung lang) OR (dung nang)) van kien soat )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( trinh han hang va hieu soat ) or ( tin ((dung lang) OR (dung nang)) van kien soat ))".
• Adding a wildcard symbol may retrieve word variants: (( trinh han hang va hieu soat ) or ( tin ((dung lang) OR (dung nang)) van kien soat ))*.