VDM '90, Kiel, Germany, VDM-Europe, Hoare, C. A. R., Langmaack, H., & Bjørner, D. (1990). VDM '90: VDM and Z : formal methods in software development : third international symposium of VDM Europe, Kiel, FRG, April 17-21, 1990 ; proceedings. Springer-Verlag.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)VDM '90, Kiel, Germany, VDM-Europe, C. A. R. Hoare, Hans Langmaack, و D. Bjørner. VDM '90: VDM and Z : Formal Methods in Software Development : Third International Symposium of VDM Europe, Kiel, FRG, April 17-21, 1990 ; Proceedings. Berlin ; New York: Springer-Verlag, 1990.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)VDM '90, Kiel, Germany, et al. VDM '90: VDM and Z : Formal Methods in Software Development : Third International Symposium of VDM Europe, Kiel, FRG, April 17-21, 1990 ; Proceedings. Springer-Verlag, 1990.