On htmlhelp.com, I need to find the HTML entity, decimal, and hexadecimal references for the copyright sign. Can you locate this information within the HTML 4 Reference section and provide all three sets of references?
Navigate to 'htmlhelp.com' Click on the 'HTML 4 Reference' link. Click on the 'HTML 4 Entities' link. Locate and extract the entity, decimal, and hexadecimal references for the 'copyright sign'. Compile and state all requested information.
Successfully identify the 'copyright sign' and provide its entity (&copy;), decimal (&#169;), and hexadecimal (&#xA9;) references. All three sets of information must be accurate and clearly stated in the final answer.