Perhaps you should try some spelling variations:
chieu xanh » chieu sach, chieu sang, chieu tinh
nhung cong » dung cong, thong cong, hang cong
tieu xanh » tieu danh, dieu hanh, tien anh
trang va » hang va
tran van » luan van
cong tap » cuong tap, cong tac, cong tan
tap toan » tap doan, tap quan, bai toan
toan cau » toan cao, toan ban, toan tap

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

• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((tieu xanh) OR (chieu xanh)) - hanh ((trang va) OR (tran van)) nhung cong tap toan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((tieu xanh) or (chieu xanh)) - hanh ((trang va) OR (tran van)) nhung cong tap toan cau~".
• Adding a wildcard symbol may retrieve word variants: theo ((tieu xanh) or (chieu xanh)) - hanh ((trang va) OR (tran van)) nhung cong tap toan cau*.