Perhaps you should try some spelling variations:
hanh tang » hanh trang, anh tang, hanh mang
cua duong » cua dong, cua huong, tuan duong
qua duong » quan duong, qua dung, qua dong
chi xanh » chi anh, chi danh, chieu xanh
chi hanh » chi nhanh, chi thanh, thi hanh
cong tap » cuong tap, cong tac, cong tan
tap toan » tap doan, tap quan, bai toan
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: doi ((chi xanh) OR (chi hanh)) - hanh tang ((cua duong) or (qua duong)) cong tap toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi ((chi xanh) OR (chi hanh)) - hanh tang ((cua duong) OR (qua duong)) cong tap toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi ((chi xanh) OR (chi hanh)) - hanh tang ((cua duong) or (qua duong)) cong tap toan cao".
• Adding a wildcard symbol may retrieve word variants: doi ((chi xanh) OR (chi hanh)) - hanh tang ((cua duong) or (qua duong)) cong tap toan cao*.