function drawChartTreatmentsPerAuthor() {
  var chartData = google.visualization.arrayToDataTable([
    ['Series', 'Number of Treatments'],
    ['Feng, Zegang & Zhang, Feng & Chen, Jun', 13],
    ['Gao, Zhizhong & Chen, Huiming & Zhang, Feng', 2],
    ['Guo, Xiangbo & Wang, Weitong & Zhang, Feng', 3],
    ['Guo, Xiangbo & Zhang, Feng', 2],
    ['Volker Mahnert & Yun-chun Li', 5],
    ['Ying, Jia & Yong-Wei, Zhao & Ming-Sheng, Zhu', 1],
    ['Ćurčić, B. P. M.', 1]
  ]);
  var chartOptions = {
    pieHole: 0,
    title: 'Treatments per Author (n=27)',
    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);