diff --git a/README.md b/README.md
index 098c61f..269d120 100644
--- a/README.md
+++ b/README.md
@@ -130,3 +130,7 @@ Copyright (c) 2018 Norbert Renner and [contributors](https://github.com/nrenner/
     Copyright (c) 2014-2021 Denis Pushkarev; [MIT License](https://github.com/zloirock/core-js/blob/master/LICENSE)
 -   [regenerator-runtime](https://github.com/facebook/regenerator/tree/master/packages/regenerator-runtime)  
     Copyright (c) 2014-present, Facebook, Inc.; [MIT License](https://github.com/facebook/regenerator/blob/master/packages/regenerator-runtime/LICENSE)
+-   [tokml](https://github.com/mapbox/tokml)  
+    Copyright (c) 2015, Mapbox All rights reserved; [BSD-2-Clause License](https://github.com/mapbox/tokml/blob/master/LICENSE.md)
+-   [Jest](https://github.com/facebook/jest)  
+    Copyright (c) Facebook, Inc. and its affiliates; [MIT License](https://github.com/facebook/jest/blob/master/LICENSE)
diff --git a/index.html b/index.html
index 6195761..e4aa5f4 100644
--- a/index.html
+++ b/index.html
@@ -1150,8 +1150,6 @@
             );
         </script>
 
-        <script src="https://unpkg.com/googlediff@0.1.0/javascript/diff_match_patch.js"></script>
-
         <script src="dist/core-js-bundle.min.js"></script>
         <script src="dist/regenerator-runtime.js"></script>
         <!-- <script src="dist/url-search-params.js"></script> -->
diff --git a/js/control/Export.js b/js/control/Export.js
index 8f94f10..3a9ce21 100644
--- a/js/control/Export.js
+++ b/js/control/Export.js
@@ -230,7 +230,6 @@ BR.Export._concatTotalTrack = function (segments) {
     let coordinates = [];
     let properties;
 
-    //console.time('_concatTotalTrack');
     for (const [segmentIndex, segment] of segments.entries()) {
         const feature = segment.feature;
         if (!feature) continue;
@@ -284,7 +283,6 @@ BR.Export._concatTotalTrack = function (segments) {
         }
         coordinates = coordinates.concat(featureCoordinates);
     }
-    //console.timeEnd('_concatTotalTrack');
 
     return turf.featureCollection([turf.lineString(coordinates, properties)]);
 };
diff --git a/js/format/Gpx.js b/js/format/Gpx.js
index de84d54..1e4ca80 100644
--- a/js/format/Gpx.js
+++ b/js/format/Gpx.js
@@ -1,3 +1,4 @@
+// derived from BRouter btools.router.OsmTrack.formatAsGpx
 BR.Gpx = {
     format: function (geoJson, turnInstructionMode = 0, transportMode = 'bike') {
         if (!geoJson?.features) return '';
@@ -72,7 +73,6 @@ BR.Gpx = {
         comment += ' plain-ascend = ' + props['plain-ascend'];
         comment += ' cost=' + props['cost'];
         if (props['total-energy']) {
-            // TODO 'wh'? (also for stats, see issue),
             // see brouter OsmTrack.getFormattedEnergy
             comment += ' energy=' + (props['total-energy'] / 3600000).toFixed(1) + 'kwh';
         }
diff --git a/js/format/VoiceHints.js b/js/format/VoiceHints.js
index bf96281..1d91c4b 100644
--- a/js/format/VoiceHints.js
+++ b/js/format/VoiceHints.js
@@ -111,6 +111,7 @@
         }
     }
 
+    // from BRouter btools.router.VoiceHint
     VoiceHints.commands = (function () {
         return {
             1: new Command('C', 1, 1002, 'Straight', 'straight'),