Estivill-Castro, Vladimir (1999), "Sorting and order statistics", in Atallah, Mikhail J. (ed.), Algorithms and Theory of Computation Handbook, Boca Raton, Florida: CRC, pp. 3-1 –3-25, MR1797171.
Griffeath, David; Hickerson, Dean (2003), "A two-dimensional cellular automaton crystal with irrational density", New constructions in cellular automata, St. Fe Inst. Stud. Sci. Complex., New York: Oxford Univ. Press, pp. 79–91, MR2079729. See in particular p. 81: "A breeder is any pattern which grows quadratically by creating a steady stream of copies of a second object, each of which creates a stream of a third."
Griffeath, David; Hickerson, Dean (2003), "A two-dimensional cellular automaton crystal with irrational density", New constructions in cellular automata, St. Fe Inst. Stud. Sci. Complex., New York: Oxford Univ. Press, pp. 79–91, MR2079729. See in particular p. 81: "A breeder is any pattern which grows quadratically by creating a steady stream of copies of a second object, each of which creates a stream of a third."