The session law for L. 1975, c. 231 is available online only from the Rutgers University School of Law Camden website. It is available as part of a scanned collection of images from the original printed books. The link below will take you to the first page of the New Jersey Legislature session volume 196_2 that contains the law. From there, use the available navigation tools to get to the appropriate chapter.
Legislative history for L. 1975, c. 231 is available from the New Jersey State Library here