Smereka, Jonathon M.; Vijaya Kumar, B. V.: 'Identifying the best periocular region for biometric recognition' (Security, 2017), 'Iris and Periocular Biometric Recognition', Chap. 6, pp. 125-147, DOI: 10.1049/PBSE005E_ch6
IET Digital Library, https://digital-library.theiet.org/;jsessionid=1i16c7s8kiot.x-iet-live-01content/books/10.1049/pbse005e_ch6