Perhaps you should try some spelling variations:
thieu xanh » chieu xanh, hieu manh, thien anh
hoc thieu » toc thieu, hoc hien
hoang van » hang va
dung cong » dung trong
hang van » hang va, dang van, tang van
cong bai » cuong bai, cong hai, cung bai
bai toan » bai tap
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 thieu xanh - hanh ((hang van) or (hoang van)) dung cong bai toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu xanh - hanh ((hang van) OR (hoang van)) dung cong bai toan cau.
• Adding a wildcard symbol may retrieve word variants: hoc thieu xanh - hanh ((hang van) or (hoang van)) dung cong bai toan cau*.