European Commission. (1998). GCAS operational requirements and certification: GORAC. Office for Official Publications of the European Communities ; Bernan Associates [distributor].
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)European Commission. GCAS Operational Requirements and Certification: GORAC. Luxembourg : Lanham, Md.: Office for Official Publications of the European Communities ; Bernan Associates [distributor], 1998.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)European Commission. GCAS Operational Requirements and Certification: GORAC. Office for Official Publications of the European Communities ; Bernan Associates [distributor], 1998.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.