Aspray, W. (1997). "The Intel 4004 microprocessor: what constituted invention?". IEEE Annals of the History of Computing. 19 (3): 4–15. doi:10.1109/85.601727. ISSN1058-6180. S2CID15782735.
Aspray, W. (1997). "The Intel 4004 microprocessor: what constituted invention?". IEEE Annals of the History of Computing. 19 (3): 4–15. doi:10.1109/85.601727. ISSN1058-6180. S2CID15782735.
"Automatic teller machine". The History of Computing Project. Thocp.net. 17 April 2006. Archived from the original on 20 February 2011. Retrieved 11 February 2011.
"Automatic teller machine". The History of Computing Project. Thocp.net. 17 April 2006. Archived from the original on 20 February 2011. Retrieved 11 February 2011.
Aspray, W. (1997). "The Intel 4004 microprocessor: what constituted invention?". IEEE Annals of the History of Computing. 19 (3): 4–15. doi:10.1109/85.601727. ISSN1058-6180. S2CID15782735.