Fix typo in integrating-with-other-libraries.md

content/docs/integrating-with-other-libraries.md

@@ -279,7 +279,7 @@ const ParagraphView = Backbone.View.extend({
 
 It is important that we also call `ReactDOM.unmountComponentAtNode()` in the `remove` method so that React unregisters event handlers and other resources associated with the component tree when it is detached.
 
-When a component is removed *from within* a React tree, the cleanup is performed automatically, but because we are removing the entire tree by hand, we must call it this method.
+When a component is removed *from within* a React tree, the cleanup is performed automatically, but because we are removing the entire tree by hand, we must call this method.
 
 ## Integrating with Model Layers