Perhaps you should try some spelling variations:
chieu tinh » trieu tinh, lieu tinh, chau tinh
hanh tranh » canh tranh, hanh trinh, hanh trang
doi chieu » doc hieu, doi chi, ho chieu
tranh cua » doanh cua, manh cua
cong cong » cong dong, trong cong, dung cong
bai toan » bai tap
van tuan » van quan, van ban, anh tuan

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 tinh - hanh tranh cua cong cong ((bai toan) OR (van tuan)) cau~.
• Adding a wildcard symbol may retrieve word variants: doi chieu tinh - hanh tranh cua cong cong ((bai toan) or (van tuan)) cau*.