// All sheets
  var overdrachtSheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName("Overdrachten");
  var inschrijvingSheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName("Inschrijvingen");
  var uitschrijvingSheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName("Uitschrijvingen");
  var vergaanvraagSheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName("Vergunningaanvraag");
  var zonetoegangSheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName("Zonetoegang");
  var playerSheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName("Spelers");

  // Get all UUID values
  var overdr_uuids = overdrachtSheet.getRange("G8:G").getValues().filter(function(uuid){ return uuid != "" });
  var inschr_uuids = inschrijvingSheet.getRange("C8:C").getValues().filter(function(uuid){ return uuid != "" });
  var uitschr_uuids = uitschrijvingSheet.getRange("C8:C").getValues().filter(function(uuid){ return uuid != "" });
  var vergaanvr_uuids = vergaanvraagSheet.getRange("C8:C").getValues().filter(function(uuid){ return uuid != "" });
  var zonetoeg_uuids = zonetoegangSheet.getRange("C8:C").getValues().filter(function(uuid){ return uuid != "" });

  // Get an array with unique UUID values only
  var unique_uuids = [];
  overdr_uuids.forEach(function(uuid){
    if(unique_uuids.indexOf(uuid[0]) < 0){
      unique_uuids.push(uuid[0]);
    }
  })

  inschr_uuids.forEach(function(uuid){
    if(unique_uuids.indexOf(uuid[0]) < 0){
      unique_uuids.push(uuid[0]);
    }
  })

  uitschr_uuids.forEach(function(uuid){
    if(unique_uuids.indexOf(uuid[0]) < 0){
      unique_uuids.push(uuid[0]);
    }
  })

  vergaanvr_uuids.forEach(function(uuid){
    if(unique_uuids.indexOf(uuid) < 0){
      unique_uuids.push(uuid[0]);
    }
  })

  zonetoeg_uuids.forEach(function(uuid){
    if(unique_uuids.indexOf(uuid) < 0){
      unique_uuids.push(uuid[0]);
    }
  })

  var setValuesArray = [];
  unique_uuids.forEach(function(uuid){
      setValuesArray.push([uuid]);
  })