Perhaps you should try some spelling variations:
hieu lang » chieu sang, hieu quang, nhieu tang
hoi hieu » hoi phieu, hoi tieu, moi hieu
mang vua » mang cua, hang va, bang va
manh cua » doanh cua, ban cua
cong bai » cuong bai, cong hai, cung bai
bai toan » bai tap
toan tap » toan ban
mang va » hang va, bang va, dang va

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoi hieu lang - hanh ((((mang vua) OR (mang va))) or (manh cua)) trong cong bai toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoi hieu lang - hanh ((((mang vua) OR (mang va))) OR (manh cua)) trong cong bai toan tap*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoi hieu lang - hanh ((((mang vua) OR (mang va))) or (manh cua)) trong cong bai toan tap*".