Referencing Google Play Services libraries in Gradle for Android


I have been having a problem with referencing Google Play Services libraries in a gradle file in my Android project. Specifically I need to reference downloader_library and zip_file library. I dont want to manually import them to my project workspace as I want to host my project on SVN later without those libraries being uploaded too. I am very new to this stuff and I am aware that my question may be confusing to some of you.