Perhaps you should try some spelling variations:
trinh quang » trinh quan, tranh quang, trinh dung
quang luan » quang tuan, quang uan, quang xuan
minh quang » dinh quang, minh hoang, minh tuan
hieu suat » hieu luat, hieu qua
luan kien » xuan kien, luan lien, quan kien
kien soat » kiem soat, bien soan, kien hoa
van hieu » cao hieu

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

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