function drawChartTreatmentsPerSource() {
  var chartData = google.visualization.arrayToDataTable([
    ['Series', 'Number of Treatments'],
    ['Johan. Christi. Trappii', 1],
    ['Journal of Natural History', 2],
    ['Phytotaxa', 1],
    ['Quarterly Journal of the Geological Society, London', 1],
    ['Report on the Scientific Results of the Voyage of H. M. S. Challenger During the Years 1873 – 76, Zoology', 10],
    ['Transactions of the geological society of London, 2', 4],
    ['ZooKeys', 2],
    ['Zoosystema', 3],
    ['Zootaxa', 32]
  ]);
  var chartOptions = {
    pieHole: 0,
    title: 'Treatments per Journal (n=56)',
    fontSize: 'automatic',
    doWeHaveDanglingCommas: 'No ;-)'
  };
  if (window.customizeGoogleChartOptions)
    customizeGoogleChartOptions(chartOptions, 'TreatmentsPerSource', 'pie', 9, 0);
  var chart = new google.visualization.PieChart(document.getElementById('chartDivTreatmentsPerSource'));
  chart.draw(chartData, chartOptions);
}
google.load('visualization', '1', {'packages': ['corechart']});
google.setOnLoadCallback(drawChartTreatmentsPerSource);