Perhaps you should try some spelling variations:
thieu xanh » hieu manh, thien anh, thien danh
chieu xanh » chieu sach, chieu sang, chieu tinh
hanh thang » nhanh thang, thanh thang, hanh trang
dung cong » dung trong
hang cong » dang cong, hang nong, bang cong
thang va » hang va, trang va, thong va
tran cau » tran chau, toan cau, ran 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 ((thieu xanh) OR (chieu xanh)) - hanh thang va ((dung cong) or (hang cong)) tan tran cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu xanh) OR (chieu xanh)) - hanh thang va ((dung cong) OR (hang cong)) tan tran cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu xanh) OR (chieu xanh)) - hanh thang va ((dung cong) or (hang cong)) tan tran cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu xanh) OR (chieu xanh)) - hanh thang va ((dung cong) or (hang cong)) tan tran cau*.