Three articles in Physical Review 57/2, January 15, 1940 Original printed wrappers. Very good condition. This seems to be the second-most cited article by Rosen following his fabulous 1935 paper with Einstein and Podolsky.
The following is taken from the APS PROLA site: "ABSTRACT Within the framework of the general theory of relativity , it is proposed to introduce at each point of space-time a Euclidean metric tensor γμν in addition to the usual Riemannian metric tensor gμν. In this way one imparts tensor character to quantities which in the usual form of the theory do not have it. For example, one can obtain a gravitational energy-momentum density tensor in place of the usual pseudo-tensor. Furthermore one can impose four additional covariant conditions on the gravitational field and thus restrict the form of the solution for the field corresponding to a given physical situation." $300.00