Laitoch, Miroslav:
К проблеме ортогональных систем функций с весом.
(Russian) [On the problem of orthogonal function systems with weight].Acta Universitatis Palackianae Olomucensis. Facultas Rerum Naturalium. Mathematica-Physica-Chemica,
vol. 1
(1960),
issue 1,
pp. 11-28