@misc{bulletinarchive1,
    type = "misc",
    author = "Peter Rowlett",
    year = "2024",
    title = {A Classical Cipher Machine: The ENIGMA - Some Aspects of its History and Solution by Robert (Bob) Churchhouse CBE FIMA (IMA President 1986-1987)},
    organization = "Institute of Mathematics and its Applications",
    url = "https://ima.org.uk/24882/a-classical-cipher-machine-the-enigma-1991/"
}