Systematic and Random Disagreement and the Reliability of Nominal Data - Krippendorff, Klaus (Communication Methods and Measures, 2008)
https://katalog.adlr.link/Record/ai-49-aHR0cDovL2R4LmRvaS5vcmcvMTAuMTA4MC8xOTMxMjQ1MDgwMjQ2NzEzNA