1. [1] D. Battaglino, A. Frosini, V. Guerrini, Binary pictures with excluded patters, Discrete Geometry for Computer Imagery, 18th IAPR International Conference, (2014), 25–38.
2. [2] S. W. Golomb, (2nd ed.), Polyominoes: Ouzzles, Patterns, Problems, and Packings, Princeton University Press, Princeton, MA, 1996.
3. [3] A. Goupil, M.-E. Pellerin, J. de Wouters d’Oplinter, Partially directed snake polyominoes, Discrete Appl. Math., 236 (2018), 223–234.
4. [4] E. Pegg Jr., https://oeis.org/A002013, 2009.
5. [5] C. Barrientos, Graceful labelings of cyclic snakes, Ars Combin., 60 (2001), 85–96.