Hence 2011 will be the 550th anniversary. {The history of the text was written by the cryptography bibliographer of the University of Pennsylvania, Charles J. Mendelson, in a 1947 article in Isis ( Mendelsohn Ch. J. Bibliographical Note on the 'De Cifris' of LeoneBattista Albert!!! Isis.-1947.-N. 32.-P. 48-51. )}

Hence 2011 will be the 550th anniversary. {The history of the text was written by the cryptography bibliographer of the University of Pennsylvania, Charles J. Mendelson, in a 1947 article in Isis ( Mendelsohn Ch. J. Bibliographical Note on the "De Cifris' of LeoneBattista Albertill Isis.-1947.-N. 32.-P. 48-51. )}