The unwritten laws of any other state or government may be proved as facts by parol evidence, or by the books of reports of cases adjudged in their courts.
Iowa Code § 622.61
Foreign unwritten law
[C51, §2444; R60, §4064; C73, §3719; C97, §4652; C24, 27, 31, 35, 39, §11314; C46, 50, 54, 58, 62, 66, 71, 73, 75, 77, 79, 81, §622.61]
Official source: Iowa Legislature. Reproduced from public-domain Iowa statutes; confirm against the official source for the current text. Not legal advice.