function drawChartTreatmentsPerAuthor() {
  var chartData = google.visualization.arrayToDataTable([
    ['Series', 'Number of Treatments'],
    ['Bütschli, Otto', 2],
    ['Dumitrica, Paulian & Zügel, Peter', 2],
    ['Ehrenberg, Christian Gottfried', 9],
    ['Haeckel, E. H. P. A.', 22],
    ['Popova, Irina M. & Baumgartner, Peter O. & Guex, Jean', 21],
    ['Tekin, Kagan & Krystyn, Leopold & Okuyucu, Cengiz & Bedi, Yavuz', 2]
  ]);
  var chartOptions = {
    pieHole: 0,
    title: 'Treatments per Author (n=58)',
    fontSize: 'automatic',
    doWeHaveDanglingCommas: 'No ;-)'
  };
  if (window.customizeGoogleChartOptions)
    customizeGoogleChartOptions(chartOptions, 'TreatmentsPerAuthor', 'pie', 6, 0);
  var chart = new google.visualization.PieChart(document.getElementById('chartDivTreatmentsPerAuthor'));
  chart.draw(chartData, chartOptions);
}
google.load('visualization', '1', {'packages': ['corechart']});
google.setOnLoadCallback(drawChartTreatmentsPerAuthor);