Here's one. Also check eBay.

Here is a link that might be useful: backpacks

I make crayon totes for small children. They fit 14 crayons in an outside 3" deep partitioned pocket. I start with fabric cut at 19 x 13 inches. They end up at 12" wide by 8" deep with a 2 1/2" squared bottom. The handles rise 6".
A coloring book fits nicely inside them.

Hope that helps you.

Dianne

I'd go check out your local library.....there are many good books out there with patterns included. Look in the sewing section and take out any books that show purses and totes I'm sure you will find something. If you wanted to save some time, call them and ask for assistance, they might pull some materials for you to have a look at. There are many quality books with just what you are looking for in publication.