function drawChartTreatmentsPerAuthor() {
  var chartData = google.visualization.arrayToDataTable([
    ['Series', 'Number of Treatments'],
    ['Christenhusz, Maarten J. M. & Zhang, Xian-Chun', 1],
    ['Hess, Hans Ernst & Landolt, Elias & Hirzel, Rosmarie', 4],
    ['Info Flora', 3],
    ['Jarvis, Charlie', 1],
    ['Konrad Lauber & Gerhart Wagner & Andreas Gygax', 3],
    ['Krefft, G.', 1],
    ['Lee, Jong-Won & Yun, Ho-Geun & Hwang, Tae Young & Kim, Kyungmin', 5],
    ['Lin, Chien-Hsiang & Brzobohatý, Rostislav & Nolf, Dirk', 1],
    ['Love, Milton S. & Bizzarro, Joseph J. & Cornthwaite, Maria', 1],
    ['Stöhr, O. & Pilsl, P. & Essl, F. & Hohla, M. & Schröck, C.', 1]
  ]);
  var chartOptions = {
    pieHole: 0,
    title: 'Treatments per Author (n=21)',
    fontSize: 'automatic',
    doWeHaveDanglingCommas: 'No ;-)'
  };
  if (window.customizeGoogleChartOptions)
    customizeGoogleChartOptions(chartOptions, 'TreatmentsPerAuthor', 'pie', 10, 0);
  var chart = new google.visualization.PieChart(document.getElementById('chartDivTreatmentsPerAuthor'));
  chart.draw(chartData, chartOptions);
}
google.load('visualization', '1', {'packages': ['corechart']});
google.setOnLoadCallback(drawChartTreatmentsPerAuthor);