To create sharing/view links for your specific classes, please follow these steps -
1. Click on Go To -> Sharing Options.
2. Ensure you have a "Student View Key" set up under the "View - Students" heading. This can be anything and is only needed to create the links.
3. Click the "Download Links" button in the upper-right corner of the "View-Students" box.
5. Open the document and copy the links to your specific classes.