Segmentation as a base for digital marketing strategies in blood service: A cluster analysis for classifying healthy regional subjectsLiliia Khomenko, Liudmyla Saher, Nataliia Letunovska and Adam JasnikowskiE3S Web Conf., 307 (2021) 03001DOI: https://doi.org/10.1051/e3sconf/202130703001