ic_2009</td>
      <td>Spatio-temporal fluctuations in the global airport hierarchies</td>
      <td>Grubesic, Tony H.; Matisziw, Timothy C.; Zook, Matthew A.</td>
      <td>2009</td>
      <td>2009-07-31</td>
      <td>PMC</td>
      <td>N</td>
      <td><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7126044" target="_blank">PMC7126044</a></td>
      <td></td>
      <td><a href="https://doi.org/10.1016/j.jtrangeo.2009.02.003" target="_blank">10.1016/j.jtrangeo.2009.02.003</a></td>
      <td>f6sl2k3n