Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
nhung cong » dung cong, thong cong, hang cong
hieu lang » chieu sang, nhieu tang, hieu van
trung cua » truong cua, trung tuan, trung cap
cong manh » cong danh, duong manh, cong thanh
manh toan » thanh toan, anh tuan, tinh toan
tang cua » mang cua, hang cua, tang luan
toan cau » toan cao, toan ban, toan tap

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