Perhaps you should try some spelling variations:
phuong quang » phung quang, thuong quang, phuong hoang
huong quang » thuong quang, luong quang, duong quang
quang tran » quang tuan, quang trung, quang thanh
hieu suat » hieu luat, hieu qua
kiem soat » kiem toan
van hieu » cao hieu
tran van » luan van
van kiem » va kiem, van kien, van hien

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tinh ((huong quang) OR (phuong quang)) van hieu suat ) or ( tinh quang tran van kiem soat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tinh ((huong quang) OR (phuong quang)) van hieu suat ) OR ( tinh quang tran van kiem soat ))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tinh ((huong quang) OR (phuong quang)) van hieu suat ) or ( tinh quang tran van kiem soat ))*".