diff --git a/enrich-citygml-with-greenarea/src/main/java/de/hft/stuttgart/citygml/green/osm/TreeKatasterData.java b/enrich-citygml-with-greenarea/src/main/java/de/hft/stuttgart/citygml/green/osm/TreeKatasterData.java
index 4f53b3a5fec7052e48f78cc30e8e1dc7709a8897..453298862eeb85e304242fc5c63485bf164699d2 100644
--- a/enrich-citygml-with-greenarea/src/main/java/de/hft/stuttgart/citygml/green/osm/TreeKatasterData.java
+++ b/enrich-citygml-with-greenarea/src/main/java/de/hft/stuttgart/citygml/green/osm/TreeKatasterData.java
@@ -43,7 +43,8 @@ public class TreeKatasterData
 
 				Point p = (Point) feature.getAttribute("the_geom");
 				if (p == null) {
-					throw new IllegalArgumentException("The shape file does not contain Point attribute with the name: \"the_geom\"");
+					throw new IllegalArgumentException(
+							"The shape file does not contain Point attribute with the name: \"the_geom\"");
 				}
 				tree.setPoint(p);
 
@@ -54,7 +55,7 @@ public class TreeKatasterData
 				}
 				tree.setType(type);
 
-				Object treeHeightObject = feature.getAttribute("Baumhöhe");
+				Object treeHeightObject = feature.getAttribute("Baumhöhe"); // [m]
 				if (treeHeightObject == null) {
 					System.out.println("Ignoring tree of type " + type + ", no attribute with name \"Baumhöhe\" found");
 					continue;
@@ -65,13 +66,13 @@ public class TreeKatasterData
 				tree.setCrownHeight(crownHeight);
 				tree.setTrunkHeight(trunkHeight);
 
-				Object crownWidth = feature.getAttribute("Kronenbrei");
+				Object crownWidth = feature.getAttribute("Kronenbrei"); // [m]
 				if (crownWidth == null) {
 					System.out.println("Ignoring tree of type " + type + ", no attribute with name \"Kronenbrei\" found");
 					continue;
 				}
 				tree.setCrownRadius(Float.parseFloat(crownWidth.toString()) / 2);
-				Object trunkCirc = feature.getAttribute("Stammumfan");
+				Object trunkCirc = feature.getAttribute("Stammumfan"); // [cm]
 				if (trunkCirc == null) {
 					System.out.println("Ignoring tree of type " + type + ", no attribute with name \"Stammumfan\" found");
 					continue;