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
tuan soan » tuan hoan, tuan hoang, luan hoan
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 quan) or (qua quan)) van hieu soat ) or ( tinh khong luan van tuan 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 tuan soan )).
• Adding a wildcard symbol may retrieve word variants: (( tinh ((quan quan) or (qua quan)) van hieu soat ) or ( tinh khong luan van tuan soan ))*.