Perhaps you should try some spelling variations:
tieu xanh » tieu danh, chieu xanh, dieu hanh
hanh manh » hanh mang, lanh manh, hoang manh
dung cong » dung trong
tap toan » tap doan, tap quan
bai toan » bai tap
manh va » hanh va, anh va, minh va
va dung » van dung, va duong, vat dung

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo tieu xanh - hanh manh va dung cong ((tap toan) OR (bai toan)) cao~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo tieu xanh - hanh manh va dung cong ((tap toan) OR (bai toan)) cao".
• Adding a wildcard symbol may retrieve word variants: theo tieu xanh - hanh manh va dung cong ((tap toan) OR (bai toan)) cao*.