Perhaps you should try some spelling variations:
dien thoai » dien hoa
luong quan » thong quan, duong qua
hieu soat » hieu suat, hieu luat, kiem soat
hieu hoat » hieu hoa, thien hoat, hieu luat
tin luong » tien luong, tin huong, tin tuong
he dien » he dieu, he lien, he mien
luan » lan

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( trinh dung luan van ((hieu soat) or (hieu hoat)) ) or ( tin luong quan he dien thoai ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( trinh dung luan van ((hieu soat) OR (hieu hoat)) ) OR ( tin luong quan he dien thoai )).
• Adding a wildcard symbol may retrieve word variants: (( trinh dung luan van ((hieu soat) or (hieu hoat)) ) or ( tin luong quan he dien thoai ))*.