(Halberstam, David Collection.) | Letter; signed inscription on photograph of him with David Halberstam. | (Knebel, Fletcher Collection.) | Letters | (McCormack, John Collection.) | Letters and note. | (Alsop, Stewart Collection.) | Letter. | (Ingersoll, Ralph Collection.) | Letter. TLS, April 25, 194- | (Wetzel, Donald Collection.) | Letter. | (Shyre, Paul Collection.) | Letters (ALS 18 and carbons, unsigned) 1968. | (Sandburg, Helga Collection.) | Letters. | (Mannes, Marya Collection.) | Letter. | (De Toledano, Ralph Collection.) | Letter, copy of. | |