Perhaps you should try some spelling variations:
chieu xanh » chieu sang, chieu tinh, hieu manh
chieu sach » chinh sach, chiet tach, chieu sang
dung cong » dung trong
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: ho ((chieu xanh) OR (chieu sach)) - thanh ((trang va) OR (tran van)) dung cong tap toan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((chieu xanh) or (chieu sach)) - thanh ((trang va) OR (tran van)) dung cong tap toan cau~".
• Adding a wildcard symbol may retrieve word variants: ho ((chieu xanh) or (chieu sach)) - thanh ((trang va) OR (tran van)) dung cong tap toan cau*.