1.
Brasche JF, Koshmanenko VD, Neidhardt H. New aspects of Krein’s extension theory. Ukr. Mat. Zhurn. [Internet]. 1994Feb.25 [cited 2024Sep.1];46(1-2):37–54. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/5768