Comparative characteristics of ultradian rhythms of critical infrastructure employees under various conditions of professional activityAnastasia Bashkireva, Sergey Chibisov, Alexander Severin, Evgeniya Severina, Tatiana Bashkireva and Alexander PrutzkowE3S Web of Conf., 381 (2023) 01035DOI: https://doi.org/10.1051/e3sconf/202338101035