Perhaps you should try some spelling variations:
thieu xanh » chieu xanh, hieu manh, thien anh
phuong dan » phuong danh, phuong doan, huong dan
hoc thieu » toc thieu, hoc hien
dan toan » van toan, dan than, manh toan
toan cau » toan cao, toan ban, toan tap
can thi » cau thi, dan thi, van thi
ca thi » cau thi, cao thi, ca thai

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu xanh - ((hanh chinh) OR (thanh cong)) ((ca thi) OR (can thi)) phuong dan toan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu xanh - ((hanh chinh) or (thanh cong)) ((ca thi) OR (can thi)) phuong dan toan cau~".
• Adding a wildcard symbol may retrieve word variants: hoc thieu xanh - ((hanh chinh) or (thanh cong)) ((ca thi) OR (can thi)) phuong dan toan cau*.