Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
canh doanh » hanh doanh, chinh doanh, doanh doanh
doanh dung » doanh chung, doanh nhung, doanh quang
hieu sang » chieu sang, hieu lang, nhieu tang
dung cong » dung trong
cong cong » cong dong, trong cong, dang cong
hoa cao » hoa co, hoa cac, hoa bao

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((hieu sang) or (hieu quang)) - canh doanh dung cong cong trinh ((hoa cao) or (hoc cao))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu sang) OR (hieu quang)) - canh doanh dung cong cong trinh ((hoa cao) OR (hoc cao)).
• Adding a wildcard symbol may retrieve word variants: doc ((hieu sang) or (hieu quang)) - canh doanh dung cong cong trinh ((hoa cao) or (hoc cao))*.