Over history there have been many books written on Demons and the various Hierarchies of Hell. Many of them are written from the Right Hand Path perspective so their titles are very insulting and not how we have experienced them at all.
It is interesting though to note the similarities and the differences in each Demonic Hierarchy, and even more fascinating to discuss each individual Demon and explore them and get a more well rounded view of them. Below you will find them listed including the publication that they can be found in.
Though we personally see then differently and have our own hierarchy that we will be posting in the future, this is a good reference point to see how the definition of the demons has evolved over time.