function drawChartTreatmentsPerAuthor() {
  var chartData = google.visualization.arrayToDataTable([
    ['Series', 'Number of Treatments'],
    ['Billberg, Gustaf Johan', 1],
    ['Kočić, Anja & Vujić, Ante & Tot, Tamara', 1],
    ['MAZáNEK, Libor & VONIČKA, Pavel & PREISLER, JiřÍ', 1],
    ['Mutin, V. A. & Barkalov, A. V.', 3]
  ]);
  var chartOptions = {
    pieHole: 0,
    title: 'Treatments per Author (n=6)',
    fontSize: 'automatic',
    doWeHaveDanglingCommas: 'No ;-)'
  };
  if (window.customizeGoogleChartOptions)
    customizeGoogleChartOptions(chartOptions, 'TreatmentsPerAuthor', 'pie', 4, 0);
  var chart = new google.visualization.PieChart(document.getElementById('chartDivTreatmentsPerAuthor'));
  chart.draw(chartData, chartOptions);
}
google.load('visualization', '1', {'packages': ['corechart']});
google.setOnLoadCallback(drawChartTreatmentsPerAuthor);