function drawChartTreatmentsPerAuthor() {
  var chartData = google.visualization.arrayToDataTable([
    ['Series', 'Number of Treatments'],
    ['Calzada, Sebastián & Forner, Enric', 1],
    ['Delgado, Marlon & Freire, Fúlvio Aurélio de Morais', 1],
    ['Gruendel, Joachim & Keupp, Helmut & Lang, Fritz', 2],
    ['Schumacher, Chrétien Fréderic', 1],
    ['Valdés, Ángel', 3]
  ]);
  var chartOptions = {
    pieHole: 0,
    title: 'Treatments per Author (n=8)',
    fontSize: 'automatic',
    doWeHaveDanglingCommas: 'No ;-)'
  };
  if (window.customizeGoogleChartOptions)
    customizeGoogleChartOptions(chartOptions, 'TreatmentsPerAuthor', 'pie', 5, 0);
  var chart = new google.visualization.PieChart(document.getElementById('chartDivTreatmentsPerAuthor'));
  chart.draw(chartData, chartOptions);
}
google.load('visualization', '1', {'packages': ['corechart']});
google.setOnLoadCallback(drawChartTreatmentsPerAuthor);