function drawChartTreatmentsPerAuthor() {
  var chartData = google.visualization.arrayToDataTable([
    ['Series', 'Number of Treatments'],
    ['Becherer', 1],
    ['Berek-Nagy, Peter Janos & Gergo Toth & Szilvia Bosze', 1],
    ['Hess, Hans Ernst & Landolt, Elias & Hirzel, Rosmarie', 4],
    ['Info Flora', 6],
    ['Ito, Yu & Barfod, Anders S.', 4],
    ['Jarvis, Charlie', 3],
    ['Jeanmonod, Daniel & éd.', 1],
    ['Konrad Lauber & Gerhart Wagner & Andreas Gygax', 5],
    ['Smith, MacKenzie A. & Greenwalt, Dale E. & Manchester, Steven R.', 1],
    ['Stöhr, O. & Pilsl, P. & Essl, F. & Wittmann, H. & Hohla, M.', 2],
    ['Verloove, Filip', 1],
    ['Zhou, Ya-Dong & Mwachala, Geoffrey & Hu, Guang-Wan', 1]
  ]);
  var chartOptions = {
    pieHole: 0,
    title: 'Treatments per Author (n=30)',
    fontSize: 'automatic',
    doWeHaveDanglingCommas: 'No ;-)'
  };
  if (window.customizeGoogleChartOptions)
    customizeGoogleChartOptions(chartOptions, 'TreatmentsPerAuthor', 'pie', 12, 0);
  var chart = new google.visualization.PieChart(document.getElementById('chartDivTreatmentsPerAuthor'));
  chart.draw(chartData, chartOptions);
}
google.load('visualization', '1', {'packages': ['corechart']});
google.setOnLoadCallback(drawChartTreatmentsPerAuthor);