function drawChartTreatmentsPerAuthor() {
  var chartData = google.visualization.arrayToDataTable([
    ['Series', 'Number of Treatments'],
    ['Harper, Margaret A. & Morales, Eduardo A. & Vijver, Bart Van De', 1],
    ['Levkov, Zlatko & Williams, David M.', 2],
    ['Ruwer, Daiane Trevisan & Rodrigues, Liliana', 2],
    ['Van de Vijver, Bart & Kusber, Wolf-Henning & Jüttner, Ingrid', 7],
    ['Van de Vijver, Bart & Peeters, Valérie & Hansen, Iris', 5],
    ['Vijver, Bart Van De', 2],
    ['Vijver, Bart Van De & Morales, Eduardo A. & Kopalová, Kateřina', 2]
  ]);
  var chartOptions = {
    pieHole: 0,
    title: 'Treatments per Author (n=21)',
    fontSize: 'automatic',
    doWeHaveDanglingCommas: 'No ;-)'
  };
  if (window.customizeGoogleChartOptions)
    customizeGoogleChartOptions(chartOptions, 'TreatmentsPerAuthor', 'pie', 7, 0);
  var chart = new google.visualization.PieChart(document.getElementById('chartDivTreatmentsPerAuthor'));
  chart.draw(chartData, chartOptions);
}
google.load('visualization', '1', {'packages': ['corechart']});
google.setOnLoadCallback(drawChartTreatmentsPerAuthor);