<aside id="case-studies">
  <h1>Case studies</h1>
  <ul>
    <% document.case_studies.each do |case_study| %>
      <%= content_tag_for(:li, case_study) do %>
        <%= link_to case_study.title, case_studies_path(case_study) %>
      <% end %>
    <% end %>
  </ul>
</aside>

<aside id="case-studies">
  <h1>Case studies</h1>
  <ul>
    <% document.case_studies.each do |case_study| %>
      <%= content_tag_for(:li, case_study) do %>
        <%= link_to case_study.title, public_document_path(case_study) %>
      <% end %>
    <% end %>
  </ul>
</aside>

Use correct document helper to generate case study link
Use correct document helper to generate case study link
