Type-4 spinors: transmuting from Elko to single-helicity spinorsC. H. Coronado Villalobos, R. J. Bueno Rogerio and F. T. São SabbasEur. Phys. J. C, 79 4 (2019) 308DOI: https://doi.org/10.1140/epjc/s10052-019-6832-2