You can find a list of your purchases if you click the menu at the top right of any Leanpub page and select "Purchases" in the menu on the left:

Or, you can just follow this link, which will take you to the "All Purchases" page:

https://leanpub.com/user_dashboard/purchases

And of course, you can also find your purchased books and courses in your library here:

https://leanpub.com/user_dashboard/library