1. Electron Spin Resonance;Poole,1967
2. Electron Paramagnetic Resonance;Alger,1968
3. Variable Temperature EPR Cryostat Cavity
4. Janis Research Company, 2 Jewel Drive, Wilmington, Massachusetts 01887.
5. Heraeus Amersil Inc., 650 Jernees Mill Road, Sayreville, New Jersey 08872.