Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
chieu xanh » chieu sang, chieu tinh, hieu manh
trong dang » truong dang, trong dan, trong dong
dang toan » dang tran, dan toan, dung toan
trung co » trung bo, truong cao, trung hoc
trong co » trong ca, trong cong, trong cuoc
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: doi ((chieu sach) OR (chieu xanh)) - manh ((trung co) OR (trong co)) dung trong dang toan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi ((chieu sach) or (chieu xanh)) - manh ((trung co) OR (trong co)) dung trong dang toan cau~".
• Adding a wildcard symbol may retrieve word variants: doi ((chieu sach) or (chieu xanh)) - manh ((trung co) OR (trong co)) dung trong dang toan cau*.