Heisenberg writes on the anomalous Zeeman effect.

Heisenberg replies to Pauli's critical remarks about his last letter.

Heisenberg writes on the quantization of the outer electron of an atom on weak external magnetic fields and in increasing fields until the Paschen-Back-effect.

Heisenberg writes on stability considerations in H$_{2}$ and about failure of the energy-calculations for He.

Heisenberg encloses a manuscript discussing certain properties of the propagation function of the non-linear wave equation. He asks for Pauli's opinion.

Heisenberg writes on excitation times and line widths.

Heisenberg writes about the quantum theory of the Zeeman effect. He makes a comparison with a paper by Bohr.

Heisenberg replies to Pauli's letter about quantum numbers. He also writes on Pauli's use of the summation principle for the calculation of Lande's g value and on the difficulties of the doublet-theory.

Heisenberg replies to Pauli's lettter and asks about the behaviour of the operator $\chi$ on the light cone.

Pauli writes about the question of whether n or k determines the total moment of the atom.