Perhaps you should try some spelling variations:
chieu tinh » trieu tinh, lieu tinh, chau tinh
tranh cua » doanh cua, manh cua
tong cong » trong cong, cong cong, dung cong
ho chieu » theo chieu, hoc thieu, doi chieu
cua tong » cua cong, cua dong, cua nong
tan toan » tan tran, tap toan, van toan
bai toan » bai tap

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ho chieu tinh - canh tranh cua tong cong ((tan toan) or (bai toan)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho chieu tinh - canh tranh cua tong cong ((tan toan) OR (bai toan)) cau*.