Uncaught ReferenceError: _ is not defined from restangular
you need to add a script reference to underscore, as is a dependency
<script src="https://cdn of underscore"></script>
restangular requires underscore/lodash` to work. Just put this dependancy before your restangular script. Also read this comment on github.
You need to add a reference of underscore.js in your html file. You can use following cdn path:
<script type="text/javascript" src="http://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.4.4/underscore-min.js"></script>