Perhaps you should try some spelling variations:
hien nhanh » hien hanh, thien thanh, tien thanh
hien xanh » hien hanh, chieu xanh, hien khanh
hanh tang » hanh trang, anh tang, hanh mang
tang luan » dung luan
dung cong » dung trong
ung cong » luong cong, duong cong, cuong cong
dan chan » dan gian, dan ca, van chat
chan cau » phan cau, can cau, chinh cau

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 xanh) or (hien nhanh)) - hanh tang luan ((ung cong) OR (dung cong)) dan chan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hien xanh) OR (hien nhanh)) - hanh tang luan ((ung cong) OR (dung cong)) dan chan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hien xanh) or (hien nhanh)) - hanh tang luan ((ung cong) OR (dung cong)) dan chan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((hien xanh) or (hien nhanh)) - hanh tang luan ((ung cong) OR (dung cong)) dan chan cau*.