1. The Allotropy of the Elements;ADDISON,1964
2. Pressure Effect in Superconductors;BOUGHTON,1970
3. Superconductivity at High Pressures;BRANDT;Contemp. Phys.,1969
4. Electronic Properties of Two New Elemental Ferromagnets: fcc Pr and Nd;BUCHER;Phys. Rev. Letters,1969
5. CIG Data Book and Buyers Guide, Cryogenics and Industrial Gases 5, No. 3 (Business Communication Inc., Cleveland, Ohio 1970) [pp. 51 ff. on E, P, Q, and S].