To read more on the Emergency Committee of Atomic Scientists and the atomic scientists movement, see these resources:
Caudill, Susan L. A New Sense of Power: Albert Einstein and the Publicity Campaign for World Government. Ph.D. Thesis, University of Tennessee, 1989.
Strickland, Donald. Scientists in Politics: The Atomic Scientists Movement, 1945-1946. Purdue University, 1968.
Wang, Jessica. American Science in an Age of Anxiety: Scientists, Anti-Communism, and the Cold War. University of North Carolina Press, 1998.
An additional archival collection for ECAS resides at the University of Chicago, along with the papers of many other scientists and organizations involved in these areas.