Editorial: Special issue on Semantic Web for Cultural Heritage. - Hitzler, Pascal; Janowicz, Krzysztof; Bikakis, Antonis; Hyvönen, Eero; Jean, Stéphane; Markhoff, Béatrice; Mosca, Alessandro; Hyvonen, Eero; Markhoff, Beatrice (Semantic Web (1570-0844), 2021)