Kozioł, Krzysztof, and Mieczysław Kula. “Witt Rings of Infinite Algebraic Extensions of Global Fields”. Annales Mathematicae Silesianae 12 (September 30, 1998): 131–139. Accessed May 8, 2025. https://trrest.vot.pl/ojsus/index.php/AMSIL/article/view/14170.