MimeTypes for Google Docs and Drive

Google Docs: application/vnd.google-apps.document
Google Presentations: application/vnd.google-apps.presentation
Google Spreadsheets: application/vnd.google-apps.spreadsheet
Google Drawing: application/vnd.google-apps.drawing

Few more of Google Docs and Google Drive MIME types:
application/vnd.google-apps.audio
application/vnd.google-apps.document
application/vnd.google-apps.drawing
application/vnd.google-apps.file
application/vnd.google-apps.folder
application/vnd.google-apps.form
application/vnd.google-apps.fusiontable
application/vnd.google-apps.kix
application/vnd.google-apps.photo
application/vnd.google-apps.presentation
application/vnd.google-apps.script
application/vnd.google-apps.sites
application/vnd.google-apps.spreadsheet
application/vnd.google-apps.unknown
application/vnd.google-apps.video