Spin splitting at the Fermi level in carbon nanotubes in the absence of a magnetic fieldMárcio M. Cunha, Júlio Brandão, Jonas R.F. Lima and Fernando MoraesEur. Phys. J. B, 88 11 (2015) 288DOI: https://doi.org/10.1140/epjb/e2015-60572-8