(a) A printed copy of a statute, or other written law, of another state, or of a territory, or of a foreign country, or a printed copy of a proclamation, edict, decree or ordinance, by the executive thereof, contained in a book or publication purporting or proved to have been published by the authority thereof, or proved to be commonly admitted as evidence of the existing law, in the judicial tribunals thereof, shall be evidence of the statute law, proclamation, edict, decree, or ordinance. The unwritten or common law of another state, or of a territory, or of a foreign country, may be proved as a fact by oral evidence. The books of the reports of cases, adjudged in the courts thereof, shall also be admitted as evidence of the unwritten or common law thereof.
(b) Any party may exhibit a copy of the law of another state, territory, or foreign country copied from a printed volume of the laws of such state, territory, or country on file in
(1) The offices of the Governor or the Secretary of State, and duly certified by the Secretary of State, or
(2) The State Library and certified as provided in G.S. 125-6, or
(3) The Supreme Court Library and certified as provided in G.S. 7A-13 (f).