Perhaps you should try some spelling variations:
hien nhanh » hien hanh, thien thanh, tien thanh
hanh trang » thanh trung, canh tranh, hanh trinh
nhung cong » dung cong, hang cong, nhung don
thong cong » trong cong, tong cong, thong thong
hieu lang » chieu sang, hieu quang, nhieu tang
trang cua » tranh cua, tang cua, trung cua
san toan » van toan, dan toan, manh toan
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: hoc ((hien nhanh) or (hieu lang)) - hanh trang cua ((nhung cong) OR (thong cong)) san toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hien nhanh) OR (hieu lang)) - hanh trang cua ((nhung cong) OR (thong cong)) san toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hien nhanh) or (hieu lang)) - hanh trang cua ((nhung cong) OR (thong cong)) san toan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((hien nhanh) or (hieu lang)) - hanh trang cua ((nhung cong) OR (thong cong)) san toan cau*.