Perhaps you should try some spelling variations:
thanh trung » thanh tung
khong cong » khong cang, chong cong, khong con
thong cong » trong cong, tong cong, thong thong
hieu lang » chieu sang, hieu quang, nhieu tang
trung cua » truong cua, trung tuan, trung cap
doi hieu » doi chieu, doc hieu, doi hien
phan cau » phan dau, phan cac, phan lap

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi hieu lang - thanh trung cua ((khong cong) OR (thong cong)) tac ((phan cau) or (phan tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi hieu lang - thanh trung cua ((khong cong) OR (thong cong)) tac ((phan cau) OR (phan tu)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi hieu lang - thanh trung cua ((khong cong) OR (thong cong)) tac ((phan cau) or (phan tu))".
• Adding a wildcard symbol may retrieve word variants: doi hieu lang - thanh trung cua ((khong cong) OR (thong cong)) tac ((phan cau) or (phan tu))*.