Megastability: Coexistence of a countable infinity of nested attractors in a periodically-forced oscillator with spatially-periodic dampingJulien C. Sprott, Sajad Jafari, Abdul Jalil M. Khalaf and Tomasz KapitaniakEur. Phys. J. Special Topics, 226 9 (2017) 1979-1985DOI: https://doi.org/10.1140/epjst/e2017-70037-1