Perhaps you should try some spelling variations:
tinh dung » trinh dung, tin dung, tinh quang
dung quan » dung quang, dung luan, luong quan
hieu soat » hieu suat, hieu hoat, hieu luat
tinh hong » tinh huong, tinh khong, tinh phong
hong quan » thong quan, tong quan, uong quan
luan kien » xuan kien, luan lien, quan kien
kien soat » kiem soat, bien soan, kien hoa
quan van » luan van, quan va, quan doan
van hieu » cao hieu

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 quan van hieu soat ) or ( tinh hong quan luan kien soat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tinh dung quan van hieu soat ) OR ( tinh hong quan luan kien soat )).
• Adding a wildcard symbol may retrieve word variants: (( tinh dung quan van hieu soat ) or ( tinh hong quan luan kien soat ))*.