Riverbank Publication No. 19 Formulae for the Solution of Geometrical Transposition Ciphers [with original folder]
Geneva, Illinois: Riverbank Laboratories 1918. First Edition. 24 pages. 22.2 x 28.6 cm. Stiff tan publisher's wraps with cover titles duplicating title page. One of 200 copies per limitation statement on copyright page. Provided in the originally issued Riverbank Laboratories button and string flapped manila envelope with matching limitation number..... More