function drawChartTreatmentsPerAuthor() {
  var chartData = google.visualization.arrayToDataTable([
    ['Series', 'Number of Treatments'],
    ['Becherer', 2],
    ['D. M. Moore (ed.)', 2],
    ['Elias Landolt', 4],
    ['H. E. Hess & E. Landolt & R. Hirzel', 2],
    ['Hess, Hans Ernst & Landolt, Elias & Hirzel, Rosmarie', 2],
    ['Info Flora', 1],
    ['Jarvis, Charlie', 1],
    ['Konrad Lauber & Gerhart Wagner & Andreas Gygax', 1],
    ['Kubentayev, Serik A. & Efimov, Petr G. & Alibekov, Daniyar T.', 1],
    ['Ormerod, Paul & Kurzweil, Hubert & Watthana, Santi', 2]
  ]);
  var chartOptions = {
    pieHole: 0,
    title: 'Treatments per Author (n=18)',
    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);