Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
thong cong » trong cong, tong cong, thong thong
hieu lang » chieu sang, nhieu tang, hieu van
hoang van » hang va
trinh han » trinh quan
dang van » hang va
han cau » hang cau, phan cau, van cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: he ((hieu lang) OR (hieu quang)) - hanh ((hoang van) or (dang van)) thong cong trinh han cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: he ((hieu lang) OR (hieu quang)) - hanh ((hoang van) OR (dang van)) thong cong trinh han cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "he ((hieu lang) OR (hieu quang)) - hanh ((hoang van) or (dang van)) thong cong trinh han cau*".