Similar title to 


    <span class="person"><a href="https://pure.iiasa.ac.at/view/iiasa/2026.html">Keyfitz, N.</a></span>
  

<span xmlns="http://eprints.org/ep3/control" class="date">(1977).</span>


    <span xmlns="http://eprints.org/ep3/control" class="title"><a href="https://pure.iiasa.ac.at/cgi/users/home?screen=EPrint::View&amp;eprintid=797"><xhtml:em xmlns:xhtml="http://www.w3.org/1999/xhtml">Understanding World Models.</xhtml:em></a></span>
  


    IIASA Research Memorandum.
  <span xmlns="http://eprints.org/ep3/control" class="publication">IIASA, Laxenburg, Austria: RM-77-018</span>