Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu xanh
chieu sang » chieu xanh, hieu lang, nhieu tang
dung cong » dung trong
cong tan » cong tac, cong san, cong thanh
tan toan » tan tran, tap toan, van toan
toan cau » toan cao, toan ban, toan tap
tang va » trang va, tang van, thang va

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 ((chieu sach) OR (chieu sang)) - hanh ((tang va) OR (hang va)) dung cong tan toan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((chieu sach) OR (chieu sang)) - hanh ((tang va) or (hang va)) dung cong tan toan cau~".
• Adding a wildcard symbol may retrieve word variants: theo ((chieu sach) OR (chieu sang)) - hanh ((tang va) or (hang va)) dung cong tan toan cau*.