Perhaps you should try some spelling variations:
trinh luong » trinh duong, trinh huong, trinh xuong
dung quang » dang quang, dung quan, luong quang
tinh dung » trinh dung, tin dung, tinh quang
quang van » quang ban, quang uan, quang va
hieu soat » hieu suat, hieu hoat, hieu luat
tien soat » trien hoat, thien hoat, kiem soat
van hieu » cao hieu
quan van » luan van, quan va, quan doan

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

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