Perhaps you should try some spelling variations:
dung tang » dung thang, dung trang, dung dang
hieu hoat » hieu hoa, thien hoat, hieu luat
hieu suat » hieu luat, hieu qua
gian lang » gian dan
lang dieu » dang dieu, sang dieu, lan dieu
tang van » dang van, hoang van, trong van
tinh qua » tinh quan, trinh qua, tinh cua
qua gian » qua giang, qua gia, qua giai
dieu hat » dieu hanh, dieu khac, dieu can

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 tang van ((hieu hoat) or (hieu suat)) ) or ( tinh qua gian lang dieu hat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tin dung tang van ((hieu hoat) OR (hieu suat)) ) OR ( tinh qua gian lang dieu hat )).
• Adding a wildcard symbol may retrieve word variants: (( tin dung tang van ((hieu hoat) or (hieu suat)) ) or ( tinh qua gian lang dieu hat ))*.