The Paper Plane is another creation of Australian bartender Sam Ross (creator of the Penicillin Cocktail). It was first created in 2007 at the Violet Hour in Chicago and originally called for Campari. In 2008 whilst tending bar at Milk & Honey Sam changed the Campari to Aperol.
Amaro Nonino isn't readily available in some countries so if this is the case for you then I recommend this variation utilising Montenegro. The drink will have a slightly different flavour profile but it still makes an incredibly tasty cocktail (and Amaro Montenegro is almost half the price!).