Woodard, Damon L.; Sundararajan, Kalaivani; Tobias, Nicole; Lyle, Jamie: 'Periocular-based soft biometric classification' (Security, 2017), 'Iris and Periocular Biometric Recognition', Chap. 9, pp. 197-212, DOI: 10.1049/PBSE005E_ch9 IET Digital Library, https://digital-library.theiet.org/;jsessionid=6k894kj794fir.x-iet-live-01content/books/10.1049/pbse005e_ch9