October 1954. Did a smile flit across his face?
Dear Doctor Zinn, Knowing the heavy schedule you have at the Laboratory, I realize the extra demand the speech before the Convention of F.B.I. Agents will make on your time and energy.
Cotter, Frank P. 1954. Cotter to Zinn, Oct. 28, 1954. “Argonne National Laboratory General Correspondence,” Box 4, Entry Series 1, RG 126. NARA, College Park, Maryland.