E. Eichten؛ K. Gottfried؛ T. Kinoshita؛ J. Kogut؛ K. D. Lane؛ T.-M. Yan (1975). "Spectrum of Charmed Quark-Antiquark Bound States". Physical Review Letters. ج. 34: 369–372. Bibcode:1975PhRvL..34..369E. DOI:10.1103/PhysRevLett.34.369.
E. Eichten؛ K. Gottfried؛ T. Kinoshita؛ J. Kogut؛ K. D. Lane؛ T.-M. Yan (1975). "Spectrum of Charmed Quark-Antiquark Bound States". Physical Review Letters. ج. 34: 369–372. Bibcode:1975PhRvL..34..369E. DOI:10.1103/PhysRevLett.34.369.