1. É.A. Manykin, M.I. Ozhovan, P.P. Poluéktov, Transition of an excited gas to a metallic state. Sov. Phys. Tech. Phys. Lett. 6, 95 (1980)
2. É.A. Manykin, M.I. Ozhovan, P.P. Poluéktov, Condensed states of excited cesium atoms. Sov. Phys. JETP 75, 440–445 (1992)
3. L. Holmlid, Classical energy calculations with electron correlation of condensed excited states—Rydberg matter. Chem. Phys. 237, 11–19 (1998)
4. S. Badiei, L. Holmlid, Lowest state n = 1 of H atom Rydberg matter: many eV energy release in Coulomb explosions. Phys. Lett. A. 327, 186–191 (2004)
5. S. Badiei, L. Holmlid, Experimental observation of an atomic hydrogen material with H–H bond distance of 150 pm suggesting metallic hydrogen. J. Phys.: Condens. Matter. 16, 7017–7023 (2004)