If you want to recover or permanently delete your Google Docs documents, you'll want to access the Google Docs trash. It's easy to find on both desktop and mobile, and we'll show you how.
See also: Google Docs: How to insert an image watermark

See also: New phishing campaign abuses Google Docs/Drive
Restore or delete documents in the Google Docs Trash on desktop
To access your deleted documents on your Windows computer, Mac, Linux, or Chromebook, use the Google Drive website. All of your deleted Google Docs are available there.
To get started, open a browser on your computer and launch the Google Drive website. Log in to your account on the site.
In the left sidebar of Drive, click “Trash.”

On the right side of the window, all deleted Google Docs documents will be displayed. This page also displays other files that you have deleted from your account.

To restore a document, select it in the list. Then, in the upper-right corner of Drive, click “Restore From Trash.”.

To permanently delete a document and free up space, select the document. Then, in the upper-right corner of Drive, click “Delete Forever” (the trash can icon).

And you're done. Your selected files are now deleted or recovered, depending on the option you chose.
See also: New Google Docs feature allows additional additions to documents
Restore or delete documents in the Google Docs Trash on mobile
If you're using an iPhone, iPad, or Android, use the Google Docs app to find your Docs recycle bin.
To get started, launch the Google Docs app on your phone. In the top left corner of the app, tap the menu with three horizontal lines.

In the menu that opens, click “Trash”.

On the “Trash” screen, you will see all your deleted Google Docs documents.

To retrieve or delete a document, next to that document's name, tap the three dots.

A menu will appear from the bottom of your phone screen. To recover the selected document, tap “Restore” in this menu. To permanently delete the selected document, tap “Delete Forever”.

You are all set.
Information source: howtogeek.com
