Copy of a letter sent from Bohr to Gagnebin about an article he wrote.

W. Heisenberg wrote to H. Kita about some mathematical problems he encountered (wrong sign in an equation and possibility of omission of a term in a conventional derivation of the Bethe-Salpeter equation). See also 1/530.

Answer to a letter from H. Kita where he pointed out a mathematical mistake in one of Heisenberg's calculations for a book or an article. See also 1/463 and 1/532.

Copy of a letter from E. Tornier to H. Bender.

Copy of a letter from E. Tornier to H. Bender.

Heisenberg is happy to see that he and Källén agree on some mathematical points (S-Matrix, Hilbertraum I, Lee-Model).

Letter from W. Pauli to Edizioni scientifiche Einaudi. Linked to the publication of "The theory of relativity".

Letter from W. Pauli to Edizioni scientifiche Einaudi. Linked to the publication of "The theory of relativity".

Letter from W. Pauli to Edizioni scientifiche Einaudi. Linked to the publication of "The theory of relativity".