JENSEN, Ole Rask. Construction of vacuum for the positive-energy representation and its Bose counterpart. MATHEMATICA SCANDINAVICA, [S. l.], v. 80, p. 101–106, 1997. DOI: 10.7146/math.scand.a-12613. Disponível em: https://tidsskrift.dk/math/article/view/12613. Acesso em: 14 aug. 2026.