Perhaps you should try some spelling variations:
hanh trinh » hanh chinh
nhung cong » dung cong, thong cong, hang cong
lieu tinh » trieu tinh, diep tinh, bien tinh
doi lieu » duoc lieu, doi chieu, du lieu
cong bai » cuong bai, cong hai, cung bai
bai toan » bai tap
toan ban » van ban

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 lieu tinh - ((canh tranh) OR (hanh trinh)) va nhung cong bai toan ban~.
• Adding a wildcard symbol may retrieve word variants: doi lieu tinh - ((canh tranh) or (hanh trinh)) va nhung cong bai toan ban*.