Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
hieu lang » chieu sang, nhieu tang, hieu van
tang luan » dung luan
dong cong » duong cong, dung cong, dang cong
tang cua » mang cua, hang cua, thong cua
cong dan » cong san, cong tan, huong dan
dan thai » dang thai, dan thi, dan than
thai cao » tai cao, thoai cac, thuat cao

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoi ((hieu lang) or (hieu quang)) - hanh ((tang cua) OR (tang luan)) dong cong dan thai cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoi ((hieu lang) OR (hieu quang)) - hanh ((tang cua) OR (tang luan)) dong cong dan thai cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoi ((hieu lang) or (hieu quang)) - hanh ((tang cua) OR (tang luan)) dong cong dan thai cao".
• Adding a wildcard symbol may retrieve word variants: hoi ((hieu lang) or (hieu quang)) - hanh ((tang cua) OR (tang luan)) dong cong dan thai cao*.