Perhaps you should try some spelling variations:
luong quan » thong quan, duong qua
tinh dung » trinh dung, tin dung, tinh quang
hieu soat » hieu suat, hieu hoat, hieu luat
dung quan » dung quang, dang quang, dung cua
xuan bien » xuan dien, xuan kien, xuan vien
van hieu » cao hieu
bien so » bien doi
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 dung luan van hieu soat ) or ( tinh ((dung quan) OR (luong quan)) xuan bien so ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tinh dung luan van hieu soat ) OR ( tinh ((dung quan) OR (luong quan)) xuan bien so )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tinh dung luan van hieu soat ) or ( tinh ((dung quan) OR (luong quan)) xuan bien so ))".
• Adding a wildcard symbol may retrieve word variants: (( tinh dung luan van hieu soat ) or ( tinh ((dung quan) OR (luong quan)) xuan bien so ))*.