 individual works and assigned a HartW number. Cyclical works such as 
          <em>Sulamiths og Salomons Sange,</em> <a class="work_number_reference" title="View work details" href="document.xq?doc=1321467871.xml">HartW 355</a>, 
          are exceptions. The same principle has been employed for collections of piano pieces 
          originally conceived as individual works (<em>Tre Klaverstykker, opus 38,</em> 
          <a class="work_number_reference" title="View work details" href="document.xq?doc