'com.ning.billing:killbill:0.1.21'
<dependency>
<groupId>com.ning.billing</groupId>
<artifactId>killbill</artifactId>
<version>0.1.21</version>
</dependency>
<dependency org="com.ning.billing" name="killbill" rev="0.1.21"/>
"com.ning.billing", "killbill", "0.1.21"