NASA, A dual telescope for spectroheliography in the extreme ultra-violet, 1966 March

NASA, A dual telescope for spectroheliography in the extreme ultra-violet, 1966 March, - 04 02 GAN 1 Sub- 4 Box 4 Folder 81, Box: 4, Folder: 81. Gordon A. Newkirk, Jr. Papers, - 04-02-GAN. National Center for Atmospheric Research (NCAR) Archives. https://aspace.archives.ucar.edu/repositories/2/archival_objects/8172 Accessed December 10, 2025.