Rozdział: The characteristics of the key elements of crowdsourcing in the core areas of social-economic activity / Anna Szwajlik. - // W: Contemporary economic challenges : changes and directions of development / Aneta Sokół, Agnieszka Budziewicz-Guźlecka, Anna Drab-Kurowska (eds.). - Aachen : Shaker Verlag GmbH, 2017 (WorkId 18061)