function drawChartTreatmentsPerAuthor() {
  var chartData = google.visualization.arrayToDataTable([
    ['Series', 'Number of Treatments'],
    ['Al-Ahmed, Azzam & Shobrak, Mohammed & Nasser, D.', 1],
    ['Gonza ́ Lez-Acun, Daniel A. & Palma, Ricardo L.', 9],
    ['Ilieva, Mihaela', 13],
    ['Ošlejšková, Lucie & Krištofík, Ján & Trnka, Alfréd', 6],
    ['Palma, Ricardo L.', 3],
    ['Palma, Ricardo L. & Peck, Stewart B.', 9],
    ['Sánchez-Montes, Sokani & Colunga-Salas, Pablo', 8],
    ['Timmermann, Günter', 2]
  ]);
  var chartOptions = {
    pieHole: 0,
    title: 'Treatments per Author (n=51)',
    fontSize: 'automatic',
    doWeHaveDanglingCommas: 'No ;-)'
  };
  if (window.customizeGoogleChartOptions)
    customizeGoogleChartOptions(chartOptions, 'TreatmentsPerAuthor', 'pie', 8, 0);
  var chart = new google.visualization.PieChart(document.getElementById('chartDivTreatmentsPerAuthor'));
  chart.draw(chartData, chartOptions);
}
google.load('visualization', '1', {'packages': ['corechart']});
google.setOnLoadCallback(drawChartTreatmentsPerAuthor);