Perhaps you should try some spelling variations:
trien hoat » tien hoa
quang van » quang ban, quan van, quang uan
hieu soat » hieu suat, hieu hoat, hieu luat
dinh dung » dinh duong, dinh hung, tinh dung
tien soat » thien hoat, kiem soat, tien hoa
ha hieu » nha hieu, va hieu, phan hieu
van ha » van hoa, van chat, van hanh
tinh » trinh, minh, kinh
luan » quan, 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 van ha 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 van ha hieu soat ) OR ( dinh dung luan van ((tien soat) OR (trien hoat)) )).
• Adding a wildcard symbol may retrieve word variants: (( tinh quang van ha hieu soat ) or ( dinh dung luan van ((tien soat) or (trien hoat)) ))*.