Perhaps you should try some spelling variations:
hieu lang » chieu sang, hieu quang, nhieu tang
hanh manh » hanh mang, lanh manh, hoang manh
dong cong » duong cong, dung cong, dang cong
manh cua » doanh cua, ban cua
cua dong » chua dong, cua cong, cua dang
bai toan » bai tap
ho hieu » ho chieu, hoi hieu, nho hieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho hieu lang - hanh manh cua dong cong ((bai toan) or (tan tran)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho hieu lang - hanh manh cua dong cong ((bai toan) OR (tan tran)) cau.
• Adding a wildcard symbol may retrieve word variants: ho hieu lang - hanh manh cua dong cong ((bai toan) or (tan tran)) cau*.