Renn, J. (2002). Echo: An infrastructure to bring European cultural heritage online ; the foundation papers of a European initiative. Max-Planck-Inst. für Wissenschaftsgeschichte.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रRenn, Jürgen. Echo: An Infrastructure to Bring European Cultural Heritage Online ; the Foundation Papers of a European Initiative. Berlin: Max-Planck-Inst. für Wissenschaftsgeschichte, 2002.
एमएलए (8वां संस्करण) प्रशस्ति पत्रRenn, Jürgen. Echo: An Infrastructure to Bring European Cultural Heritage Online ; the Foundation Papers of a European Initiative. Max-Planck-Inst. für Wissenschaftsgeschichte, 2002.
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