Demuth, Osvald:
Об oднoм oбoбщeнии кoнcтpуктивнoгo интеграла Лeбeгa.
(Russian) [A generalization of the constructive Lebesgue integral].Commentationes Mathematicae Universitatis Carolinae,
vol. 18
(1977),
issue 3,
pp. 499-514
Demuth, Osvald:
Об одном конструктивном аналоге функций $n$-ого класса Бэра.
(Russian) [A constructive analogue of the functions of the $n$-th Baire class].Commentationes Mathematicae Universitatis Carolinae,
vol. 18
(1977),
issue 2,
pp. 231-245