Forgotten Legions by Anthony Munoz covers collaborationist SS units, and has chapters on Handschar, Kama and Skanderbeg. Munoz also wrote
The East Came West about Arab and,
inter alia, Hindu(!) volunteers for the Axis; interesting read. There’s a brief discussion of the Bosnian Muslim units
here, about 2/3 of the way down.
For a discussion of how Kosovo’s SS past was prologue to its present, check this out. Yeah, Trop, I know it’s emperors-clothes, but so what.