function drawChartTreatmentsPerAuthor() {
  var chartData = google.visualization.arrayToDataTable([
    ['Series', 'Number of Treatments'],
    ['Ivkovic, Marija & Doric, Valentina & Baranov, Viktor', 2],
    ['Ivkovic, Marija & Perovic, Marija & Grootaert, Patrick', 4],
    ['Ivković, Marija & Gračan, Romana & Horvat, Bogdan', 5],
    ['Ivković, Marija & Zamora-Muñoz, Carmen & Sainz-Bariaín, Marta', 1],
    ['Ivković, Marija & Čorkalo, Marko & Tkoč, Michal', 2],
    ['Shamshev, Igor V. & Ivković, Marija', 1]
  ]);
  var chartOptions = {
    pieHole: 0,
    title: 'Treatments per Author (n=15)',
    fontSize: 'automatic',
    doWeHaveDanglingCommas: 'No ;-)'
  };
  if (window.customizeGoogleChartOptions)
    customizeGoogleChartOptions(chartOptions, 'TreatmentsPerAuthor', 'pie', 6, 0);
  var chart = new google.visualization.PieChart(document.getElementById('chartDivTreatmentsPerAuthor'));
  chart.draw(chartData, chartOptions);
}
google.load('visualization', '1', {'packages': ['corechart']});
google.setOnLoadCallback(drawChartTreatmentsPerAuthor);