HAJDUOVÁ, Zuzana - LACKO, Roman. ISO Standards, Six Sigma and Lean Six Sigma Application Possibilities in Healthcare Management. In Acta oeconomica Cassoviensia : scientific journal. - Košice : PHF EU Košice, 2016. ISSN 1337-6020, 2016, roč. 9, č. 2, s. 52-59. I-16-140-00.