N.J. Stat. Ann. § 1:6-4

Proof of the publications required by sections 1:6-1 and 1:6-3 of this title shall be by oath or affirmation in writing, made by the publisher, or his authorized agent, of every newspaper in which publication was made. The proof shall contain a copy of the published notice, and shall be presented with the bill when introduced, and, after final vote on the bill, shall be filed and deposited by the officers of the legislature in whose hands it may be in the office of the secretary of state, there to remain.