Perhaps you should try some spelling variations:
tran hoang » tran hong, quan hoang, tran quang
tuan hoang » quan hoang, xuan hoang, luan hoan
tinh quan » tinh quang, trinh quan, tin quan
hieu soat » hieu suat, hieu hoat, hieu luat
tinh dung » trinh dung, tin dung, tinh quang
van hieu » cao hieu
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 quan luan van hieu soat ) or ( tinh dung luan van ((tuan hoang) OR (tran hoang)) ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tinh quan luan van hieu soat ) OR ( tinh dung luan van ((tuan hoang) OR (tran hoang)) )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tinh quan luan van hieu soat ) or ( tinh dung luan van ((tuan hoang) OR (tran hoang)) ))".
• Adding a wildcard symbol may retrieve word variants: (( tinh quan luan van hieu soat ) or ( tinh dung luan van ((tuan hoang) OR (tran hoang)) ))*.