Perhaps you should try some spelling variations:
nhieu tang » chieu sang, hieu lang, nhiet nang
hieu quang » thieu quang, hieu quan, hieu qua
hanh trinh » canh tranh, hanh chinh
trinh quan » tinh quang, trinh luat, trinh han
quan dong » quang dong, quan long, quan hoang
dong cong » duong cong, dung cong, dang cong
bai toan » bai tap

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: ho ((nhieu tang) OR (hieu quang)) - hanh trinh quan dong cong ((bai toan) OR (tan tran)) cau~.
• Adding a wildcard symbol may retrieve word variants: ho ((nhieu tang) or (hieu quang)) - hanh trinh quan dong cong ((bai toan) or (tan tran)) cau*.