Medvedev, V.K. (1994) “Coordinate system and combinatorial objects (an example of a generalized quadrangle)”,
Ukrains’kyi Matematychnyi Zhurnal, 46(5), pp. 516–523. Available at:
https://umj.imath.kiev.ua/index.php/umj/article/view/5715 (Accessed: 10 April 2025).