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

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