References request: two-queue, one-server model with pre-emptive queue priority and finite buffers

Question

Sorry of the title is a mouthful. I'm developing a queue model with the following characteristics:

1. Two queues: One contains an infinite number of people (Queue A) while the other (Queue B) is initially empty and has a finite size of $L$ people.
2. Alternatively, Queue A can be thought of as having a finite size with no arrival rate, but each person served from Queue A goes right back to the end of Queue A (i.e., recycling of persons).
3. Queue B has exponentially distributed interarrival times of rate $\lambda$.
4. The server has exponentially distributed service times of rate $\mu$
5. Service Discipline: Persons in Queue B have preemptive priority over persons in Queue A.

Question/request: Looking for literature that has assessed this type of situation. I have seen literature on a single queue with different classes of persons (with pre-emptive or non-preemptive priority) and on modeling two finite queues, but nothing like this. Hoping someone more familiar with the literature can provide some pointers.