Perhaps you should try some spelling variations:
dung tran » dung trang, dung tren, hung tran
tinh quan » tinh quang, trinh quan, tin quan
quan quan » quan quang, qua quan, quan luan
hieu soat » hieu suat, hieu hoat, kiem soat
hieu luat » hieu qua
tran van » luan van
van kiem » va kiem, van kien, van hieu
quan van » luan van, quan va, quan luan

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

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