Perhaps you should try some spelling variations:
chieu xanh » chieu sang, chieu tinh, hieu manh
chieu sach » chinh sach, chiet tach, chieu sang
chinh khoa » chinh cho, sinh khoa, chi khoa
hang cong » hang nong, bang cong, thanh cong
dang cong » dung cong
dan toan » van toan, dan than, manh 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 ((chieu xanh) or (chieu sach)) - hanh chinh khoa ((hang cong) OR (dang cong)) dan toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi ((chieu xanh) OR (chieu sach)) - hanh chinh khoa ((hang cong) OR (dang cong)) dan toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi ((chieu xanh) or (chieu sach)) - hanh chinh khoa ((hang cong) OR (dang cong)) dan toan cao".
• Adding a wildcard symbol may retrieve word variants: doi ((chieu xanh) or (chieu sach)) - hanh chinh khoa ((hang cong) OR (dang cong)) dan toan cao*.