Trithemius’ Poligraphia, Giambattista Porta’s De Furtivis Literarum Notis, De Vigenere’s Traite des Chiffres, Falconer’s Cryptomenysis Patefacta, Davys’ and Thicknesse’s eighteenth-century treatises, and such fairly modern authorities as Blair, van Marten and Kluber’s script itself,
