function drawChartTreatmentsPerAuthor() {
  var chartData = google.visualization.arrayToDataTable([
    ['Series', 'Number of Treatments'],
    ['Alexander, Timothy & Seehausen, Ole', 3],
    ['Artaev, Oleg & Ruchin, Alexander B.', 1],
    ['Bianco, Pier Giorgio & Ketmaier, Valerio', 2],
    ['Bogutskaya, Nina G. & Iliadou, K.', 1],
    ['Calderoni, P.', 1],
    ['Eagderi, Soheil & Mouludi-Saleh, Atta & Esmaeili, Hamid Reza', 2],
    ['Gratzianov, V. J.', 1],
    ['Jordan, David Starr & Evermann, Barton Warren', 1],
    ['Kovalchuk, O. М.', 2],
    ['Nurettin Meriç & Lütfiye Eryilmaz & Müfit Özulug', 2],
    ['Sayyadzadeh, Golnaz & Esmaeili, Hamid Reza', 2],
    ['Stephanidis, A.', 1],
    ['Çiçek, Erdoğan & Fricke, Ronald & Eagderi, Soheil', 1]
  ]);
  var chartOptions = {
    pieHole: 0,
    title: 'Treatments per Author (n=20)',
    fontSize: 'automatic',
    doWeHaveDanglingCommas: 'No ;-)'
  };
  if (window.customizeGoogleChartOptions)
    customizeGoogleChartOptions(chartOptions, 'TreatmentsPerAuthor', 'pie', 13, 0);
  var chart = new google.visualization.PieChart(document.getElementById('chartDivTreatmentsPerAuthor'));
  chart.draw(chartData, chartOptions);
}
google.load('visualization', '1', {'packages': ['corechart']});
google.setOnLoadCallback(drawChartTreatmentsPerAuthor);