Glavan, V.A. (1993) “The structure of linear extensions with the Favard type conditions II. Linear extensions with the additivity property of recurrent motions”,
Ukrains’kyi Matematychnyi Zhurnal, 45(4), pp. 466–471. Available at:
https://umj.imath.kiev.ua/index.php/umj/article/view/5833 (Accessed: 10 April 2025).