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
hieu suat » hieu luat, hieu qua
kiem soat » kiem toan
quang ma » xquang ma, quang va, quang manh
quan van » luan van, quan va, quan doan
ma hieu » va hieu, ma sieu, manh hieu

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 ma hieu suat ) or ( trinh luong ((quan van) or (quan luan)) kiem soat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tinh dung quang ma hieu suat ) OR ( trinh luong ((quan van) OR (quan luan)) kiem soat )).
• Adding a wildcard symbol may retrieve word variants: (( tinh dung quang ma hieu suat ) or ( trinh luong ((quan van) or (quan luan)) kiem soat ))*.