Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
trung tuan » trung thanh, trung tam, tran tuan
nhung cong » dung cong, thong cong, hang cong
dang thanh » dong thanh, dang hanh, hoang thanh
hieu sang » chieu sang, hieu lang, nhieu tang
trung cua » truong cua, trung cap, dung cua
cong dang » cong dong, cong dan, cong dung
thanh van » thanh san, thanh toan, thanh phan

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)) - hanh ((trung cua) or (trung tuan)) nhung cong dang thanh van~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu sang) OR (hieu quang)) - hanh ((trung cua) OR (trung tuan)) nhung cong dang thanh van.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu sang) OR (hieu quang)) - hanh ((trung cua) or (trung tuan)) nhung cong dang thanh van".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu sang) OR (hieu quang)) - hanh ((trung cua) or (trung tuan)) nhung cong dang thanh van*.