India- WWI POW camps

I recently saw a card of 1915 addressed to Germany from Dinapur Concentration camp. Dinapur is a small garrison town near Patna, Bihar, India.Alan Baker does not list this camp. This card has the proper POW free post rubber stamp and has" Prisoner of War Mail " caption on it. Has an additional Bombay censor mark too.
In the past ten years , I have also seen such cards from other small places in India where the sender was most likely held in house arrest and still the cards had POW caption on them and were censored by civil censors. Is there any comprehensive work on the situation of POWs in India apart from Baker and that Red cross report?
Viswa
In the past ten years , I have also seen such cards from other small places in India where the sender was most likely held in house arrest and still the cards had POW caption on them and were censored by civil censors. Is there any comprehensive work on the situation of POWs in India apart from Baker and that Red cross report?
Viswa