Git Clone a Specific Version/Tag/Branch

I am trying to learning guava implementation detail. So I git-clone the source code as described here.
https://code.google.com/p/guava-libraries/source/checkout
git clone https://code.google.com/p/guava-libraries/
Cloning into 'guava-libraries'...
error: error setting certificate verify locations:
  CAfile: chrome\depot_tools\git-1.8.0_bin/bin/curl-ca-bundle.crt
  CApath: none
 while accessing https://code.google.com/p/guava-libraries/info/refs?service=git-upload-pack
fatal: HTTP request failed
I changed from https to http:
git clone http://code.google.com/p/guava-libraries/ 

It works, then I ran "mvn eclipse:eclipse, it failed with the following exception:
[ERROR] Failed to execute goal on project guava-testlib: Could not resolve dependencies for project com.google.guava:guava-testlib:jar:16.0-SNAPSHOT: Failure to find com.google.guava:guava:jar:16.0-SNAPSHOT in https://oss.sonatype.org/content/repositories/snapshots was cached in the local repository, resolution will not be reattempted until the update interval of sonatype-nexus-snapshots has elapsed or updates are forced -> [Help 1]

So I tried to check out the old version: release 15.0.
I run command: git clone tag and dint the tag name of release 15.0: v15.0

To change local repo to release 15.0, I use: git checkout vlocal_15.0 -b v15.0
The format is: git checkout ] -b remote_branch_name.

Then run mvn eclipse:eclipse and mvn install, it works

To directly clone release 15.0, we can use:
git clone http://code.google.com/p/guava-libraries/  -b v15.0
Resources
git-clone manual page
http://stackoverflow.com/questions/3231079/how-to-see-all-tags-in-a-git-repository-in-command-line
http://stackoverflow.com/questions/791959/how-to-use-git-to-download-a-particular-tag