function drawChartTreatmentsPerAuthor() {
  var chartData = google.visualization.arrayToDataTable([
    ['Series', 'Number of Treatments'],
    ['Becherer', 2],
    ['Cabezudo, Baltasar & Solanas, Federico Casimiro-Soriguer', 1],
    ['Essl, F.', 1],
    ['Essl, F. & A, Lower & A, Lower', 2],
    ['Essl, F. & Stöhr, O.', 4],
    ['Hess, Hans Ernst & Landolt, Elias & Hirzel, Rosmarie', 3],
    ['Info Flora', 15],
    ['Jarvis, Charlie', 1],
    ['Jeanmonod, Daniel & éd.', 1],
    ['Konrad Lauber & Gerhart Wagner & Andreas Gygax', 8],
    ['Li, Mingwan & Li, Dan & Lu, Mengfei & Mo, Shuangfeng', 1],
    ['Niaki, Nemat Allah Raei & Attar, Farideh & Zamani, Asghar', 8],
    ['Stöhr, O. & Pilsl, P. & Essl, F. & Hohla, M. & Schröck, C.', 5],
    ['Stöhr, O. & Pilsl, P. & Essl, F. & Wittmann, H. & Hohla, M.', 2],
    ['Sáez, Llorenç & Rosselló, Josep A.', 8],
    ['Other (1)', 1]
  ]);
  var chartOptions = {
    pieHole: 0,
    title: 'Treatments per Author (n=63)',
    fontSize: 'automatic',
    doWeHaveDanglingCommas: 'No ;-)'
  };
  if (window.customizeGoogleChartOptions)
    customizeGoogleChartOptions(chartOptions, 'TreatmentsPerAuthor', 'pie', 16, 0);
  var chart = new google.visualization.PieChart(document.getElementById('chartDivTreatmentsPerAuthor'));
  chart.draw(chartData, chartOptions);
}
google.load('visualization', '1', {'packages': ['corechart']});
google.setOnLoadCallback(drawChartTreatmentsPerAuthor);