Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
trinh luan » trinh luat, trinh quan, trinh han
bien tinh » bi tinh, yen tinh, diep tinh
dung cong » dung trong
hang cong » dang cong, hang nong, bang cong
dan thanh » dang thanh, danh thanh, ban thanh
thanh ban » thanh san, thanh van, thanh bac
so bien » mot bien

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: so bien tinh - hanh trinh luan ((dung cong) OR (hang cong)) dan thanh ban~.
• Adding a wildcard symbol may retrieve word variants: so bien tinh - hanh trinh luan ((dung cong) or (hang cong)) dan thanh ban*.