(1) Any return, declaration, statement or other document required to be made pursuant to the income tax provisions of the Nebraska Revenue Act of 1967 shall be signed in accordance with regulations or instructions prescribed by the Tax Commissioner. The fact that an individual's name is signed to a return, declaration, statement or other document, shall be prima facie evidence for all purposes that the return, declaration, statement or other document was actually signed by him, and that said individual was authorized to sign the return, declaration, statement or other document.

(2) The making or filing of any return, declaration, statement, or other document or copy of a federal return, shall constitute a certification by the person making or filing such return, declaration, statement or other document or copy thereof that the statements contained therein are true and that any copy filed is a true copy.