function drawChartTreatmentsPerAuthor() {
  var chartData = google.visualization.arrayToDataTable([
    ['Series', 'Number of Treatments'],
    ['Breure, Abraham S. H. & Tardy, Emmanuel', 1],
    ['Essl, F. & A, Lower & A, Lower', 1],
    ['Hess, Hans Ernst & Landolt, Elias & Hirzel, Rosmarie', 2],
    ['Howell, Nathan & Krings, Alexander & Braham, Richard R', 2],
    ['Info Flora', 2],
    ['Jarvis, Charlie', 2],
    ['Konrad Lauber & Gerhart Wagner & Andreas Gygax', 2],
    ['Kovar-Eder, Johanna & Kvaček, Zlatko & Teodoridis, Vasilis', 1],
    ['Kvaček, Zlatko & Teodoridis, Vasilis & Radoň, Miroslav', 1],
    ['Martinetto, Edoardo & Bertini, Adele & Mantzouka, Dimitra', 1],
    ['Smith, MacKenzie A. & Greenwalt, Dale E. & Manchester, Steven R.', 1],
    ['Stöhr, O. & Pilsl, P. & Essl, F. & Hohla, M. & Schröck, C.', 1],
    ['Suh, Soo-Jung', 1],
    ['Teodoridis, Vasilis & Kvaček, Zlatko & Radoň, Miroslav', 1],
    ['Wheeler, Elisabeth A. & Manchester, Steven R.', 1]
  ]);
  var chartOptions = {
    pieHole: 0,
    title: 'Treatments per Author (n=20)',
    fontSize: 'automatic',
    doWeHaveDanglingCommas: 'No ;-)'
  };
  if (window.customizeGoogleChartOptions)
    customizeGoogleChartOptions(chartOptions, 'TreatmentsPerAuthor', 'pie', 15, 0);
  var chart = new google.visualization.PieChart(document.getElementById('chartDivTreatmentsPerAuthor'));
  chart.draw(chartData, chartOptions);
}
google.load('visualization', '1', {'packages': ['corechart']});
google.setOnLoadCallback(drawChartTreatmentsPerAuthor);