Perhaps you should try some spelling variations:
thieu quang » thien quan, trien quang, hieu quan
thanh trung » thanh tung
hieu quang » hieu quan, hieu qua, diep quang
cong thanh » dong thanh, cong trinh, truong thanh
trung cua » truong cua, trung tuan, trung cap
cua trong » cua truong, cua trung, qua trong
cong tan » cong tac, cong san, cong ty
than cap » khan cap, thanh lap, thanh cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((hieu quang) or (thieu quang)) - thanh trung cua trong ((cong tan) OR (cong thanh)) than cap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu quang) OR (thieu quang)) - thanh trung cua trong ((cong tan) OR (cong thanh)) than cap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hieu quang) or (thieu quang)) - thanh trung cua trong ((cong tan) OR (cong thanh)) than cap".
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu quang) or (thieu quang)) - thanh trung cua trong ((cong tan) OR (cong thanh)) than cap*.