We have a paper under review (since a year) describing the architecture in detail. We plan to extend the documentation on the website in the meantime.
As a sidenote: Our implementation predates the Cardano blockchain name
Can't find anything either, not sure if there is. On the other hand, they seem to reference research done around "Recursive InterNetwork Architecture" (RINA). Publication page is at [0]. Maybe also of interest some other RINA implementations: [1], [2].