Wolfgang Pauli and M.E. Rose, "Remarks on the Polarization Effects in the Positron Theory, in the Physical Review, vol. 49, Issue 6, pp. 462-46. Original wrappers. Fine copy. $200
Abstract from PROLA: "A simple method of obtaining the induced charge-density four vector on the basis of the subtraction formalism of the positron theory is given. Further, in the general case of time-dependent fields the result is calculated directly without use of the Lorentz invariance of the theory."