Section 973 - Signing of returns and other documents(a) General. Any return, statement or other document required to be made pursuant to this article shall be signed in accordance with instructions prescribed by the commissioner of taxation and finance.(b) Signature presumed authentic. The fact that the name of the executor or other individual is signed to a return, statement or other document, or copies thereof, shall be prima facie evidence for all purposes that the return, statement or other document, or copy was actually signed by him.(c) Certifications. The making or filing of any return, statement or other document, or copy thereof, required to be made or filed pursuant to this article, including a copy of a federal return, shall constitute a certification by the person making or filing such return, statement or other document or copy thereof that the statements contained therein are true and that any copy filed is a true copy.