Perhaps you should try some spelling variations:
tinh khong » tinh khang, tinh huong, benh khong
khong quan » thong quan, hong quan, thong quang
hieu soat » hieu suat, hieu hoat, hieu luat
tuan soan » tuan hoan, tuan hoang, luan hoan
quan van » luan van, quan va, quan doan
van hieu » cao hieu
van tuan » van quan, van ban, anh tuan

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