KLEIN, Felix (1849-1925). Two papers from the Comptes rendus:
(1) “Formes principales sur les surfaces de Riemann”, in Comptes Rendus, 21 January 1889, volume 108 #3, pp 134-136 in the issue of pp 113-156.
(2) “Des fonctions theta sur la surface generale de Riemann”, in Comptes Rendus, 1889, volume 108 #6, pp 277-280 in the issue of pp 261-315.
Both weekly issues removed from a larger bound volume, and offered together at $150.
“Klein…saw his work on function theory as his major contribution to mathematics. As W Burau and B Schoenberg write:
Klein considered his work in function theory to be the summit of his work in mathematics. He owed some of his greatest successes to his development of Riemann’s ideas and to the intimate alliance he forged between the later and the conception of invariant theory, of number theory and algebra, of group theory, and of multidimensional geometry and the theory of differential equations, especially in his own fields, elliptic modular functions and automorphic functions.”–St. Andrews History of Math site.