Library Shelf Alphabetize Google Sheet

Code.gs

// adapted from https://webapps.stackexchange.com/questions/84218/sorting-alphabetically-a-z-ignoring-beginning-a-an-and-the-using-a-scri
function sortByTitle() {
  var sheet = SpreadsheetApp.getActiveSheet();
  // Ignore header row (A1:Z1)
  var range = sheet.getRange(2, 1, sheet.getLastRow() - 1, sheet.getLastColumn());
  var values = range.getValues();
  values.sort(function(a,b) {return (trimmed(a[0]) < trimmed(b[0]) ? -1 : 1);});
  range.setValues(values);
}

function trimmed(str) {
  return str.toLowerCase().replace(/^(a|an|the) /, ''); 
}

function onOpen() {
  SpreadsheetApp.getActiveSpreadsheet().addMenu("Sort", [{name: "by Title",  functionName: "sortByTitle"}]);
}