‎"SONIN, N. (NIKOLAY YAKOVLEVICH).‎
‎(Sur la fonction discontinue (x) et ses applications par N. Sonin). In Russian, but transcribed by the author in his own hand on the title-page.‎

‎Varsovie, 1889. Orig. printed wrappers. (2),78 pp. Inscribed to the Danish mathematician Niels E. Nørlund: ""A Monsieur N. Nörlund/ hommage de l'auteur"" together with the title translated into French by Sonin.‎

Reference : 58149

‎First edition. ""Sonin made a substantial contribution to the theory of special functions" the unifying idea of his researches was to establish a few convenient definitions of initial notions and operations leading to broad and fruitful generalizations of these functions.... From 1901 to 1915 president of the Scientific Committee of the Ministry of National Education. With A. A. Markov, Sonin prepared a two-volume edition of the works of Chebyshev in Russian and French. (DSB).‎