Perhaps you should try some spelling variations:
bien tinh » yen tinh, diep tinh, ban tinh
tang luan » dung luan
dung cong » dung trong
tang cua » mang cua, hang cua, thong cua
cong bai » cuong bai, cong hai, cung bai
bai toan » bai tap
toan ban » van ban
bi tinh » vi tinh

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo ((bien tinh) OR (bi tinh)) - hanh ((tang cua) or (tang luan)) dung cong bai toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((bien tinh) OR (bi tinh)) - hanh ((tang cua) OR (tang luan)) dung cong bai toan ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((bien tinh) OR (bi tinh)) - hanh ((tang cua) or (tang luan)) dung cong bai toan ban".
• Adding a wildcard symbol may retrieve word variants: theo ((bien tinh) OR (bi tinh)) - hanh ((tang cua) or (tang luan)) dung cong bai toan ban*.