function drawChartTreatmentsPerAuthor() {
  var chartData = google.visualization.arrayToDataTable([
    ['Series', 'Number of Treatments'],
    ['Ghahari, Hassan & Moulet, Pierre', 4],
    ['Goula, Marta & Valcárcel, Javier Pérez', 2],
    ['Krüger, Andreas & Deckert, Jürgen', 1],
    ['Roca-Cusachs, Marcos & Suárez, Daniel & Osorio, Víctor', 1],
    ['Valcárcel, Javier Pérez & Goula, Marta & Piloña, Fernando Prieto', 2],
    ['Vinokurov, Nikolay N. & Rudoi, Valentin V.', 1],
    ['Çerçi, Barış & Koçak, Özgür & Tezcan, Serdar', 1]
  ]);
  var chartOptions = {
    pieHole: 0,
    title: 'Treatments per Author (n=12)',
    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);