A. http://www.pagesz.net/~stevek/intellect/press.html

B. http://www.slip.net/~graphion/guten.html

Lehmann-Haupt Gutenberg and the Master of the Playing Cards Yale University Press 1966

Winship "Gutenberg to Plantin" Burt Franklin New York, New York, 1968

Jones, "Marsh" Lecture notes

Scholderer Johann Gutenberg The Inventor of Printing Harvard Press, 1960