1. Wells, D. R. (1999). The Birds of the Thai-Malay Peninsula. Volume 1. Non-passerines. Academic Press, London, UK.
2. Rasmussen, P. C., and J. C. Anderton (2005). Birds of South Asia. The Ripley Guide. Volumes 1 and 2. Smithsonian Institution, Washington, DC, USA and Lynx Edicions, Barcelona, Spain.
3. König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK.
4. Leadprathom K., Chimchome V. and Bumrungsri S. (2009). Nesting ecology of the Collared Scops Owl Otus lettia in Thailand. Ardea. 97(4): 457–461.
5. Wells, D. R. (1999). The Birds of the Thai-Malay Peninsula. Volume 1. Non-passerines. Academic Press, London, UK.