Clements, J. F., T. S. Schulenberg, M. J. Iliff, D. Roberson, T. A. Fredericks, B. L. Sullivan, and C. L. Wood. 2019. The eBird/Clements checklist of birds of the world: v2019. Downloaded from http://www.birds.cornell.edu/clementschecklist/download/ (連結)