From the Robin Catalogue:
A. MS., notebook, G-1903-2a, October 12, 1903, pp. 68-126; A1-A8.
Published, in part, as 1.521-544 (pp. 68-126, with only the first and last paragraphs deleted). Pages A1-A8, unpublished, are mainly a reply to a listener’s note asking, “What makes a Reasoning to be sound?” The note itself (dated November 27, 1903) has been inserted opposite p. A1. Also unpublished is material on the beta part of existential graphs.