Some scholars also expressed concern that the reference set a precedent for enforcing unwritten rules. This could lead to even wider grounds for judicial review. The study of unwritten rules is also said to have surfaced in the Supreme Court decisions "New Brunswick Broadcasting Co. v. Nova Scotia (Speaker of the House of Assembly)" (1993) and "Reference re Secession of Quebec" (1998), and one scholar called it a "very old and venerable" feature of common law. Conversely, one critic, who claimed the 1997 Reference represented the first time that the unwritten constitution was used to invalidate a statute in Canada, said that courts had consequently grown "bolder in their law-creating enterprise" and that "If law requires certainty, unwritten principles are bound to create problems."