4 Jun 1942, FBI memo, Edward Tamm to Hoover — reports on N. J. L. Pieper meetings with Ennis and DeWitt
4 Jun 1942, FBI memo, Report on N. J. L. Pieper meetings
4 Jun 1942, FBI memo, Edward Tamm to Hoover — reports on N. J. L. Pieper meetings with Ennis and DeWitt