YubiKey Tools for Developers - What is YubiKey? (Part 3)
How the YubiKey Works
YubiKey 5 NFC – Yubico
Security Key C NFC – Yubico
Information, Free Full-Text
YubiKey FIPS (4 Series) Deployment Considerations – Yubico
Duo Administration - Use YubiKeys for with Duo
personalization Pilot service for Yubikey two-factor authentication
Shop Yubico - YubiKey 5C NFC - Two-Factor authentication (2FA) Security Key, Connect via USB-C or NFC, FIDO Certified - Protect Your Online Accounts
YubiKey 5C NFC - Two Factor Authentication USB and NFC Security Key