Smith LA and Spiegel EA  ‘ Strange accumulators” https:leonardsmithuswpcontentuploadsStrangeAccumu

Smith, L.A. and Spiegel, E.A. 1987 ‘Strange accumulators, in chaos in astrophysics‘, Annals of the New York Academy of Science, 497: 61-65. DOI: 10.1111/j.1749-6632.1987.tb48711.x.