||Paris: Alphonse Leduc, n.d.(1880). Plate A.L. 5039.
||This may be the 1873 publication instead (the work was released by Leduc twice, in 1873 and in 1880. The plate suggests this is the 1873 pub. see below.)
||20 études caractéristiques pour violon
Publication noted in the Bibliographie de la France
2e série, 69e année, Nº 12, 20 Mars 1880, page 153, registration 981.
The plate table suggests an earliest publication date closer to 1873. Not denying it was published in 1880, but maybe it might have been published earlier too? -- update: yes; see BNF.