text: const fs = require('fs');
  
  let rawdata = fs.readFileSync('db.json');
  let entries = JSON.parse(rawdata);
  var noYearReferences = [];
  var years = [];
  var outliers = [];
  
  for (const entry in entries) {
      var references = entries[entry].references;
      for (const referenceId in references) {
          var reference = references[referenceId];
          if (reference.year == null) {
              noYearReferences.push(reference);
          } else {
              years.push(reference.year);
              if (reference.year <= 1900 || reference.year > 2021) {
                  // console.log(reference);
                  outliers.push(reference);
              }
          }
      }
  }
  
  // console.log(noYearReferences.length);
  for (const year of years) {
      if (year <=1900 || year>2021) {
          
      }
      // console.log(year);
  }