How to include assets from external library into Angular CLI project

I am trying below but this does not work,

```
  "assets": [
    "../node_modules/<external library>/assets/"
  ]

```

Scripts are working fine though,

```
 "scripts": [  
    "../node_modules/<external library>/some.js",     
    "startup.js"
 ]

```

Angular Version : 2.4.1

Angular CLI : 1.0.0-beta.24

Any suggestion?