König, C. and Weick, F. 2008. Owls of the World. Christopher Helm, London.
Lasco, R.; Pulhin, F.; Bugayong, L.; Mendoza, M. 2011. An assessment of potential benefits to smallholders of REDD+ components in the Philippines. Annals of Tropical Research 33(1): 31-48.
Suarez, R. K.; Sajise, P. E. 2010. Deforestation, swidden agriculture and Philippine biodiversity. Philippine Science Letters 3(1): 91-99.
Uitamo, E. 1999. Modelling deforestation caused by the expansion of subsistence farming in the Philippines. J. Forest Economics 5(1): 99-122.
Walpole, P. 2010. Figuring the Forest Figures: Understanding Forest Cover Data in the Philippines and where we might be proceeding. Environmental Science for Social Change, Quezon City, Philippines Available at: essc.org.ph.
BirdLife International (2020) Species factsheet: Ninox randi. Downloaded from http://www.birdlife.org on 18/01/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 18/01/2020.