Perhaps you should try some spelling variations:
quang quan » quang tuan, quang uan, quan quan
trien hoat » tien hoa
hieu soat » hieu suat, hieu hoat, hieu luat
dinh dung » dinh duong, dinh hung, tinh dung
tien soat » thien hoat, kiem soat, tien hoa
quan vi » quan li, quan tri, quan doi
vi hieu » vi dieu, va hieu, vo hieu
tinh » trinh, minh, kinh
luan » lan

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

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