Perhaps you should try some spelling variations:
hanh tranh » canh tranh, hanh trinh, hanh trang
nhung cong » thong cong, hang cong, nhung don
dung cong » dung trong
theo hoi » theo doi, theo hop, theo duoi
hoi lang » hoa lang, hoi dan
tranh va » tranh van, trang va, trinh va
toan cao » toan tap
toan ban » van ban

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo hoi lang - hanh tranh va ((nhung cong) OR (dung cong)) dan ((toan cao) or (toan ban))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo hoi lang - hanh tranh va ((nhung cong) OR (dung cong)) dan ((toan cao) OR (toan ban)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo hoi lang - hanh tranh va ((nhung cong) OR (dung cong)) dan ((toan cao) or (toan ban))".
• Adding a wildcard symbol may retrieve word variants: theo hoi lang - hanh tranh va ((nhung cong) OR (dung cong)) dan ((toan cao) or (toan ban))*.