Perhaps you should try some spelling variations:
thieu xanh » chieu xanh, hieu manh, thien anh
hoc thieu » toc thieu, hoc hien
tranh cua » doanh cua, manh cua
hang cong » dang cong, hang nong, bang cong
cua hang » cua dang, cua nhung, cua cong
tan toan » tan tran, tap toan, van toan
bai toan » bai 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 - canh tranh cua hang cong ((tan toan) or (bai toan)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu xanh - canh tranh cua hang cong ((tan toan) OR (bai toan)) cau*.