Clicking on the “Additional Terms” shows the following:

Section 11.1 of the Terms of Service governing Google Docs is replaced in its entirety by:

“You retain copyright and any other rights you already hold in Content which you submit, post or display on or through, the Service. By submitting, posting or displaying the Content you give Google a worldwide, royalty-free, and non-exclusive license to reproduce, adapt, modify, translate, publish, publicly perform, publicly display and distribute any Content which you submit, post or display on or through the Service for the sole purpose of enabling Google to provide you with the Service in accordance with its Privacy Policy.” (Emphasis added.)

For Google Docs (e.g., a book you might publish) this section replaces the section 11.1 you cited, and the important difference is that they can only reproduce your work for the purpose of providing the service (i.e., so that you can actually have access to your documents).