Perhaps you should try some spelling variations:
thieu quang » hieu quang, thien quan, trien quang
thong cong » trong cong, tong cong, thong thong
hieu lang » chieu sang, hieu quang, nhieu tang
tinh cua » trinh cua, sinh cua, tranh cua
cong dan » cong san, cong tan, huong dan
dan than » dan chan, ban than, van than
than cao » toan cao, thai cao, than cap

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 (thieu quang)) - hanh ((tinh cua) OR (tinh chat)) thong cong dan than cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoi ((hieu lang) OR (thieu quang)) - hanh ((tinh cua) OR (tinh chat)) thong cong dan than cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoi ((hieu lang) or (thieu quang)) - hanh ((tinh cua) OR (tinh chat)) thong cong dan than cao".
• Adding a wildcard symbol may retrieve word variants: hoi ((hieu lang) or (thieu quang)) - hanh ((tinh cua) OR (tinh chat)) thong cong dan than cao*.