Mel'nichenko, I.P. and Plaksa, S.A. (1995) “Reduction of the principal biharmonic problem for a quadrant to nonsingular integral equations”, Ukrains’kyi Matematychnyi Zhurnal, 47(6), pp. 775–784. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/5471 (Accessed: 14 April 2025).