Perhaps you should try some spelling variations:
tranh van » tran van, trinh van, thanh van
dung cong » dung trong
hang cong » dang cong, hang nong, bang cong
chi tinh » chai tinh, chi minh, chi binh
dan toan » van toan, dan than, manh toan
toan cao » toan ban, toan tap
doi chi » doi khi

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi chi tinh - canh tranh van ((dung cong) or (hang cong)) dan toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi chi tinh - canh tranh van ((dung cong) OR (hang cong)) dan toan cao.
• Adding a wildcard symbol may retrieve word variants: doi chi tinh - canh tranh van ((dung cong) or (hang cong)) dan toan cao*.