function drawChartTreatmentsPerAuthor() {
  var chartData = google.visualization.arrayToDataTable([
    ['Series', 'Number of Treatments'],
    ['Becherer', 3],
    ['Info Flora', 3],
    ['Ito, Yu & Barfod, Anders S.', 2],
    ['Kapitonova, Olga A.', 1],
    ['Konrad Lauber & Gerhart Wagner & Andreas Gygax', 3],
    ['Oliveira, Adriana & Bove, Claudia', 2],
    ['Stöhr, O. & Pilsl, P. & Essl, F. & Hohla, M. & Schröck, C.', 1],
    ['Stöhr, O. & Pilsl, P. & Essl, F. & Wittmann, H. & Hohla, M.', 1]
  ]);
  var chartOptions = {
    pieHole: 0,
    title: 'Treatments per Author (n=16)',
    fontSize: 'automatic',
    doWeHaveDanglingCommas: 'No ;-)'
  };
  if (window.customizeGoogleChartOptions)
    customizeGoogleChartOptions(chartOptions, 'TreatmentsPerAuthor', 'pie', 8, 0);
  var chart = new google.visualization.PieChart(document.getElementById('chartDivTreatmentsPerAuthor'));
  chart.draw(chartData, chartOptions);
}
google.load('visualization', '1', {'packages': ['corechart']});
google.setOnLoadCallback(drawChartTreatmentsPerAuthor);