Carta a José María Eguren, 21/11/1928
Carta a José María Eguren, 25/2/1929
Carta a Samuel Glusberg, 10/6/1929
Carta a Samuel Glusberg, 20/6/1929
Carta a Samuel Glusberg, 21/8/1929
Carta a Samuel Glusberg, 9/2/1930
Carta a Samuel Glusberg, 6/3/1930
Carta a Samuel Glusberg, 11/3/1930
Carta de Samuel Glusberg, 6/12/1928
Carta de Enrique López Albújar, 6/2/1928
Carta de Fortunato Zora Carvajal, 18/9/1929
Carta a Ricardo Vegas García, [11/1925]