Simmons, G. J. (1985). "The Subliminal Channel and Digital Signatures". In Beth, T.; Cot, N.; Ingemarsson, I. (eds.). Proceedings of Eurocrypt '84. Lecture Notes in Computer Science. Vol. 209. Springer-Verlag. pp. 364–378. doi:10.1007/3-540-39757-4_25. ISBN978-3-540-16076-2.
Simmons, G. J. (1993). "Subliminal Communication is Easy Using the DSA". In Helleseth, T. (ed.). Proceedings of Eurocrypt '93. Lecture Notes in Computer Science. Vol. 765. Springer-Verlag. pp. 218–232. doi:10.1007/3-540-48285-7_18. ISBN978-3-540-57600-6.