Choe, Choi & Moon 2003, p. 850. - Choe, Heemahn; Choi, Sung-Soon; Moon, Byung-Ro (2003). Cantù-Paz, Erick (ed.). A Hybrid Genetic Algorithm for the Hexagonal Tortoise Problem. Proceedings of the Genetic and Evolutionary Computation (GECCO) Conference, Chicago, IL, USA, July 12–16, 2003. Springer. ISBN 978-3-540-40602-0.
Choe, Choi & Moon 2003, p. 850. - Choe, Heemahn; Choi, Sung-Soon; Moon, Byung-Ro (2003). Cantù-Paz, Erick (ed.). A Hybrid Genetic Algorithm for the Hexagonal Tortoise Problem. Proceedings of the Genetic and Evolutionary Computation (GECCO) Conference, Chicago, IL, USA, July 12–16, 2003. Springer. ISBN 978-3-540-40602-0.