Perhaps you should try some spelling variations:
chieu xanh » chieu sach, chieu sang, hieu manh
chieu tinh » trieu tinh, lieu tinh, chau tinh
dang trong » dung trong, dong trong, lang trong
trung cap » truong cao
trong bai » trong ban, thong bai, trong hai
bai toan » bai tap
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 tinh)) - thanh ((trung cap) OR (trung tam)) dang trong bai toan cao~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((chieu xanh) or (chieu tinh)) - thanh ((trung cap) OR (trung tam)) dang trong bai toan cao~".
• Adding a wildcard symbol may retrieve word variants: ho ((chieu xanh) or (chieu tinh)) - thanh ((trung cap) OR (trung tam)) dang trong bai toan cao*.