The source code of the following dlls can be copied from official Google project:
http://code.google.com/p/google-gdata/source/checkout
Google.GData.Client
Google.GData.Contacts.dll
Google.GData.Extensions.dll
Use this command to anonymously check out the latest project source code:
# Non-members may check out a read-only working copy anonymously over HTTP.
svn checkout http://google-gdata.googlecode.com/svn/trunk/ google-gdata-read-only