Dirac, Paul Adrien MauriceProceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character,114,1927,p.243–265. Bibcode: 1927RSPSA.114..243D. DOI: 10.1098/rspa.1927.0039[Consulta: free].
Dirac, Paul Adrien MauriceProceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character,114,1927,p.243–265. Bibcode: 1927RSPSA.114..243D. DOI: 10.1098/rspa.1927.0039[Consulta: free].