diff --git a/README.md b/README.md
index 8d049af..e9d405f 100644
--- a/README.md
+++ b/README.md
@@ -7,7 +7,7 @@ Parses [WMS](http://en.wikipedia.org/wiki/Web_Map_Service) capabilities XML form
 
 ## Usage
 
-### Browserify
+### ES
 ```
 npm install wms-capabilities --save
 ```
@@ -17,6 +17,8 @@ import WMSCapabilities from 'wms-capabilities';
 new WMSCapabilities().parse(xmlString);
 //or
 new WMSCapabilities(xmlString).toJSON();
+// or 
+new WMSCapabilities().readFromDocument(xmldoc);
 ```
 ### Browser
 ```html
diff --git a/src/index.js b/src/index.js
index 0bf2d19..11810b8 100644
--- a/src/index.js
+++ b/src/index.js
@@ -42,7 +42,7 @@ export default class WMS {
 
   /**
    * @param  {String=} xmlString
-   * @return {Object}
+   * @return {Object|null}
    */
   toJSON (xmlString) {
     xmlString = xmlString || this._data;
@@ -51,16 +51,17 @@ export default class WMS {
 
   /**
    * @return {String} xml
+   * @return {Object|null}
    */
   parse (xmlString) {
-    return this._readFromDocument(this._parser.toDocument(xmlString));
+    return this.readFromDocument(this._parser.toDocument(xmlString));
   }
 
   /**
    * @param  {Document} doc
-   * @return {Object}
+   * @return {Object|null}
    */
-  _readFromDocument (doc) {
+  readFromDocument (doc) {
     for (let node = doc.firstChild; node; node = node.nextSibling) {
       if (node.nodeType == nodeTypes.ELEMENT) {
         return this.readFromNode(node);