Perhaps you should try some spelling variations:
luong thiet » luong thien, luong thit, luong tiet
trinh xay » trinh ky
dung tan » dung toan, duong tan, dung tai
van chat » cao chat
ke quang » khe quang, le quang, de quang
tan van » tran van, tang van, luan van
ke quan » ve quan, te quan, he quan

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

• Performing a fuzzy search may retrieve terms with similar spellings: cong trinh xay dung tan van chat luong thiet ((ke quang) or (ke quan)) yen~.
• If you are trying to use Boolean operators, they must be ALL CAPS: cong trinh xay dung tan van chat luong thiet ((ke quang) OR (ke quan)) yen.
• Adding a wildcard symbol may retrieve word variants: cong trinh xay dung tan van chat luong thiet ((ke quang) or (ke quan)) yen*.