If you know the groupId and aritifactId,you can generate download url like this.
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
<version>1.2.3</version>
</dependency>
http://central.maven.org/maven2/ch/qos/logback/logback-classic/
and you will get a page like this, chose the version you need,just enjoy it!