Perhaps you should try some spelling variations:
trinh quan » tinh quang, trinh luat, trinh han
quang doan » quan doan, quang hoan, quang toan
hieu soat » hieu suat, hieu hoat, hieu luat
doan hien » doan thien, doan dien, don hien
hien soat » thien hoat, kiem soat, bien soan
van hieu » cao hieu
anh tran » anh tuan, anh toan, anh trac
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: (( trinh quan luan van hieu soat ) or ( anh tran quang doan hien soat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( trinh quan luan van hieu soat ) OR ( anh tran quang doan hien soat )).
• Adding a wildcard symbol may retrieve word variants: (( trinh quan luan van hieu soat ) or ( anh tran quang doan hien soat ))*.