Ecological tourism public marketing: responses to grand challenges Olena Uhodnikova, Nataliia Bogdan, Mariia Pokolodna, Olhа Radionova and Kostiantyn Viatkin E3S Web Conf., 217 (2020) 05003 Published online: 14 December 2020 DOI: 10.1051/e3sconf/202021705003