Perhaps you should try some spelling variations:
thien hoat » trien hoat, thien thuat, tien hoa
quang quan » quang tuan, quang uan, quan quan
hieu suat » hieu luat, hieu qua
dinh dung » dinh duong, dinh hung, tinh dung
tien soat » trien hoat, kiem soat, tien hoa
quan va » quan vi, quan ha, luan va
va hieu » van hieu, va dieu, va hien
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 va hieu suat ) or ( dinh dung luan van ((tien soat) or (thien hoat)) ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tinh quang quan va hieu suat ) OR ( dinh dung luan van ((tien soat) OR (thien hoat)) )).
• Adding a wildcard symbol may retrieve word variants: (( tinh quang quan va hieu suat ) or ( dinh dung luan van ((tien soat) or (thien hoat)) ))*.