Calculating and Interpreting Cohen's Kappa in Excel - YouTube
ReCal3: Reliability for 3+ Coders – Deen Freelon, Ph.D.
AgreeStat/360: computing weighted agreement coefficients (Conger's kappa, Fleiss' kappa, Gwet's AC1/AC2, Krippendorff's alpha, and more) for 3 raters or more