Renn, J. ECHO - an infrastructure to bring European cultural heritage online: Jürgen Renn. Echo : an infrastructure to bring European cultural heritage online ; the foundation papers of a European initiative.(2002).
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Renn, Jürgen. "ECHO - an Infrastructure to Bring European Cultural Heritage Online: Jürgen Renn." Echo : An Infrastructure to Bring European Cultural Heritage Online ; the Foundation Papers of a European Initiative.(2002) .
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Renn, Jürgen. "ECHO - an Infrastructure to Bring European Cultural Heritage Online: Jürgen Renn." Echo : An Infrastructure to Bring European Cultural Heritage Online ; the Foundation Papers of a European Initiative.(2002), .
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.