function drawChartTreatmentsPerAuthor() {
  var chartData = google.visualization.arrayToDataTable([
    ['Series', 'Number of Treatments'],
    ['Arnoult, J.', 1],
    ['Berkenkamp, H. O.', 2],
    ['Berkenkamp, H. O. & Etzel, V.', 3],
    ['Fowler, Henry Weed', 1],
    ['Gill, T. N.', 1],
    ['Mayer, F.', 1],
    ['Paul V. Loiselle', 2],
    ['Poll, M.', 3],
    ['Romand, R.', 1],
    ['Résumé, Jacques Daget', 1],
    ['Schultze, O.', 1],
    ['Sonnenberg, Rainer & Busch, Eckhard', 1],
    ['Van Der Zee, Jouke R. & Mbimbi Mayi Munene, José J.', 1]
  ]);
  var chartOptions = {
    pieHole: 0,
    title: 'Treatments per Author (n=19)',
    fontSize: 'automatic',
    doWeHaveDanglingCommas: 'No ;-)'
  };
  if (window.customizeGoogleChartOptions)
    customizeGoogleChartOptions(chartOptions, 'TreatmentsPerAuthor', 'pie', 13, 0);
  var chart = new google.visualization.PieChart(document.getElementById('chartDivTreatmentsPerAuthor'));
  chart.draw(chartData, chartOptions);
}
google.load('visualization', '1', {'packages': ['corechart']});
google.setOnLoadCallback(drawChartTreatmentsPerAuthor);