Babbage, C. (1856). An analysis of the statistics of the clearing house during the year 1839: With an appendix on the London and New York clearing houses, and on the Condon Railway clearing house. London: John Murray.

Babbage, Charles. An Analysis of the Statistics of the Clearing House During the Year 1839: With an Appendix On the London and New York Clearing Houses, and On the Condon Railway Clearing House. London: John Murray, 1856.

Babbage, Charles. An Analysis of the Statistics of the Clearing House During the Year 1839: With an Appendix On the London and New York Clearing Houses, and On the Condon Railway Clearing House. London: John Murray, 1856.