Fellah, A.; Jürgensen, H.; Yu, S. (1990). "Constructions for alternating finite automata∗". International Journal of Computer Mathematics. 35 (1–4): 117–132. doi:10.1080/00207169008803893. ISSN0020-7160.
Theorem 19 of Holzer, Markus; Kutrib, Martin (2011-03-01). "Descriptional and computational complexity of finite automata—A survey". Information and Computation. 209 (3): 456–470. doi:10.1016/j.ic.2010.11.013. ISSN0890-5401.
Fellah, A.; Jürgensen, H.; Yu, S. (1990). "Constructions for alternating finite automata∗". International Journal of Computer Mathematics. 35 (1–4): 117–132. doi:10.1080/00207169008803893. ISSN0020-7160.
Theorem 19 of Holzer, Markus; Kutrib, Martin (2011-03-01). "Descriptional and computational complexity of finite automata—A survey". Information and Computation. 209 (3): 456–470. doi:10.1016/j.ic.2010.11.013. ISSN0890-5401.