Perhaps you should try some spelling variations:
cong thanh » dong thanh, cong tan, truong thanh
hiem ngan » kim ngan, viem gan
hieu lang » chieu sang, hieu quang, nhieu tang
hanh tang » hanh trang, anh tang, hanh mang
cua thong » cua thuong, cua khong, cua tong
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: theo ((hiem ngan) or (hieu lang)) - hanh tang cua thong ((cong thanh) OR (cong trinh)) toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((hiem ngan) OR (hieu lang)) - hanh tang cua thong ((cong thanh) OR (cong trinh)) toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((hiem ngan) or (hieu lang)) - hanh tang cua thong ((cong thanh) OR (cong trinh)) toan cau".
• Adding a wildcard symbol may retrieve word variants: theo ((hiem ngan) or (hieu lang)) - hanh tang cua thong ((cong thanh) OR (cong trinh)) toan cau*.