This subspecies is apparently not found in the Oriental Region but the images are placed here as representative of the species pending acquisition of images of Glaucidium passerinum orientale which differs in being generally greyer and with clearer white spots.
König, C., Weick, F. & Becking, J-H. (1999) Owls - A Guide to the Owls of the World Pica Press. Sussex, UK.
Howard & Moore Complete Checklist of the Birds of the World. (3rd edn., 2003)