How versions are available in Google api client and how do I get previous versions of Google api?

[askquestion118]

Google play services client library

just started developing apps in andriod. I have few questions on google api client. I came to know they moved from GooglePlayServicesClientl to GoogleApiClient.html.

i have few questions?
1. How many versions are available in google api client?
2. How to get previous versions of google api client (google play services lib)

Thanks for replying