Perhaps you should try some spelling variations:
trien hoat » tien hoa
quang uan » quang tuan, quang ban, quang tran
hieu soat » hieu suat, hieu hoat, hieu luat
van trien » van tien, va trien, van tren
dung lam » dung luan, dung tai, dung dat
uan cao » juan cao, quang cao, nang cao
lam van » lam san, nam van, dam van
tinh » trinh, minh, kinh

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( (tinh OR dinh) quang uan cao hieu soat ) or ( tin dung lam van trien hoat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( (tinh OR dinh) quang uan cao hieu soat ) OR ( tin dung lam van trien hoat ))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( (tinh OR dinh) quang uan cao hieu soat ) or ( tin dung lam van trien hoat ))*".