function drawChartTreatmentsPerSource() {
  var chartData = google.visualization.arrayToDataTable([
    ['Series', 'Number of Treatments'],
    ['Bey dem Verfasser zu finden', 2],
    ['E. W. Jansen', 1],
    ['Insect Systematics and Diversity', 2],
    ['The Journal of Research on the Lepidoptera', 3],
    ['ZooKeys', 3],
    ['Zoological Research', 1],
    ['Zootaxa', 4]
  ]);
  var chartOptions = {
    pieHole: 0,
    title: 'Treatments per Journal (n=16)',
    fontSize: 'automatic',
    doWeHaveDanglingCommas: 'No ;-)'
  };
  if (window.customizeGoogleChartOptions)
    customizeGoogleChartOptions(chartOptions, 'TreatmentsPerSource', 'pie', 7, 0);
  var chart = new google.visualization.PieChart(document.getElementById('chartDivTreatmentsPerSource'));
  chart.draw(chartData, chartOptions);
}
google.load('visualization', '1', {'packages': ['corechart']});
google.setOnLoadCallback(drawChartTreatmentsPerSource);