Trends and Future Research in Electronic Marketing: A Bibliometric Analysis of Twenty Years. - Peng Gao; Fanchen Meng; Mário Nuno Mata; José Moleiro Martins; Shahid Iqbal; Anabela Batista Correia; Rui Miguel Dantas; Abdul Waheed; João Xavier Rita; Muhammad Farrukh (J. Theor. Appl. Electron. Commer. Res., 2021)