1. Unique Identification Authority of India, AADHAAR: http://uidai.gov.in.
2. NEXUS: Joint USA and Canada Trusted Traveler Program, US official site: https://www.cbp.gov/travel/trusted-traveler-programs/nexus; Canada official site: http://www.nexus.gc.ca.
3. ISO/IEC 30107-1, Information technology – Biometric presentation attack detection – Part 1: Framework, 2016.
4. Presentation attack detection for iris recognition: an assessment of the state-of-the-art;Czajka;ACM Comput. Surv.,2018
5. Synthesizing iris images using RaSGAN with application in presentation attack detection;Yadav,2019