«Olivetti Programma P101/P102». Old Computers. Archivado desde el original el 9 de junio de 2016. Consultado el 11 de agosto de 2010. «The P101, and particularly the magnetic card, was covered by a US patent (3,495,222, Perotto et al.) and this gave to Olivetti over $900.000 in royalties by HP alone, for the re-use of this technology in the HP9100 series.»
oldcalculatormuseum.com
«Programma 101». Old Calculator Web Museum. Consultado el 25 de agosto de 2015.
«Olivetti Programma P101/P102». Old Computers. Archivado desde el original el 9 de junio de 2016. Consultado el 11 de agosto de 2010. «The P101, and particularly the magnetic card, was covered by a US patent (3,495,222, Perotto et al.) and this gave to Olivetti over $900.000 in royalties by HP alone, for the re-use of this technology in the HP9100 series.»
