Perhaps you should try some spelling variations:
tinh khang » tinh khong, trinh khung, tinh thanh
khang luan » hang luan, khanh luan, khung luan
hieu soat » hieu suat, hieu hoat, hieu luat
bien soan » bien so
quan van » quan va, quan luan, quan doan
van hieu » cao hieu
van bien » van tien, van hien, vat bien
luat » xuat

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (( ((trinh luat) or (tinh quang)) quan van hieu soat ) or ( tinh khang luan van bien soan ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( ((trinh luat) OR (tinh quang)) quan van hieu soat ) OR ( tinh khang luan van bien soan )).
• Adding a wildcard symbol may retrieve word variants: (( ((trinh luat) or (tinh quang)) quan van hieu soat ) or ( tinh khang luan van bien soan ))*.