Evolution of the Web of Social Machines: A Systematic Review and Research Challenges. - Kellyton dos Santos Brito; Alysson Alves de Lima; Sérgio Endrigo Ferreira; Vanilson André de Arruda Burégio; Vinicius Cardoso Garcia; Silvio Romero de Lemos Meira (IEEE Trans. Comput. Soc. Syst., 2020)