«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.»
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«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.»
