Adkins, G. S., R. N. Fell, et J. Sapirstein.2000. "Order α2 Corrections to the Decay Rate of Orthopositronium."Physical Review Letters 84, no. 22 (29 Maii): 5086–89.doi:10.1103/PhysRevLett.84.5086.PMID 10990873. Arxiv hep-ph/0003028. Bibcode 2000PhRvL..84.5086A. S2cid=1165868.
Badertscher, A., P. Crivelli, W. Fetscher, U. Gendotti, S. N. Gninenko, V. Postoev, A. Rubbia, V. Samoylenko, et D. Sillou.2007. "An Improved Limit on Invisible Decays of Positronium."Physical Review D 75 (3): 032004.doi:10.1103/PhysRevD.75.032004. Arxiv hep-ex/0609059. Bibcode 2007PhRvD..75c2004B. S2cid=9001914.
Cooke, D. A., P. Crivelli, J. Alnis, A. Antognini, B. Brown, S. Friedreich, A. Gabard, T. W. Haensch, K. Kirch, A. Rubbia, et B. Vrankovic.2015. "Observation of positronium annihilation in the 2S state: towards a new measurement of the 1S-2S transition frequency."Hyperfine Interact 233 (1–3): 67–73.doi:10.1007/s10751-015-1158-4. Arxiv 1503.05755. Bibcode 2015HyInt.233...67C. S2cid=89605682.
Czarnecki, Andrzej, et Savely G. Karshenboim.l2000. "Decays of Positronium."Proceedings of the International Workshop on High Energy Physics and Quantum Field Theory, ed. B. B. Levchenko et V. I. Savrin, 14: 538–44. Arxiv hep-ph/9911410. Bibcode 1999hep.ph...11410C.
Karshenboim, Savely G.2003. "Precision Study of Positronium: Testing Bound State QED Theory."International Journal of Modern Physics A 19 (23): 3879–96.doi:10.1142/S0217751X04020142. Arxiv hep-ph/0310099. Bibcode 2004IJMPA..19.3879K. S2cid=14848837.
Mohorovičić, Stjepan.1934. "Möglichkeit neuer Elemente und ihre Bedeutung für die Astrophysik."Astronomische Nachrichten 253 (4): 93–108.doi:10.1002/asna.19342530402. Bibcode 1934AN....253...93M.