function drawChartTreatmentsPerAuthor() {
  var chartData = google.visualization.arrayToDataTable([
    ['Series', 'Number of Treatments'],
    ['Bueno-Villegas, Julián & Sierwald, Petra', 1],
    ['Christenhusz, Maarten J. M. & Zhang, Xian-Chun', 1],
    ['De Zoysa, H. K. S. & Nguyen, Anh D. & Wickramasinghe, S.', 2],
    ['Hollier, John & Stöckli, Eduard & Wesener, Thomas', 7],
    ['John Hollier & Edmund Schiller & Nesrine Akkari', 2],
    ['Keller, Oliver & Dunn, Ann & Soto-Adames, Felipe', 2],
    ['Likhitrakarn, Natdanai & Golovatch, Sergei I. & Panha, Somsak', 2],
    ['Pugh, P. J. A.', 1],
    ['Read, Helen J. & Enghoff, Henrik', 12],
    ['Riquelme, Francisco & Hernández-Patricio, Miguel', 1],
    ['SU, YI-TONG & CAI, CHEN-YANG & HUANG, DI-YING', 2],
    ['Wesener, Thomas', 1],
    ['Wesener, Thomas & Moritz, Leif', 1]
  ]);
  var chartOptions = {
    pieHole: 0,
    title: 'Treatments per Author (n=35)',
    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);