function drawChartTreatmentsPerAuthor() {
  var chartData = google.visualization.arrayToDataTable([
    ['Series', 'Number of Treatments'],
    ['Barahona-Segovia, Rodrigo M. & Puiggros, Andrés', 1],
    ['Batelka, Jan', 2],
    ['Batelka, Jan & Hájek, Jiří', 3],
    ['Batelka, Jan & Straka, Jakub', 1],
    ['Bosc, L. A. G.', 1],
    ['Iskandarova, Tukazban & Japarashvili, Shota', 1],
    ['Straka, Jakub & Batelka, Jan & Pauly, Alain', 1]
  ]);
  var chartOptions = {
    pieHole: 0,
    title: 'Treatments per Author (n=10)',
    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);