C. Michael Holloway. "Why Engineers Should Consider Formal Methods". 16th Digital Avionics Systems Conference (27-30 October 1997). Diakses pada 16 November 2006. "Salinan arsip"(PDF). Diarsipkan dari asli(PDF) tanggal 2012-06-06. Diakses tanggal 2007-09-03.
C. Michael Holloway. "Why Engineers Should Consider Formal Methods". 16th Digital Avionics Systems Conference (27-30 October 1997). Diakses pada 16 November 2006. "Salinan arsip"(PDF). Diarsipkan dari asli(PDF) tanggal 2012-06-06. Diakses tanggal 2007-09-03.