Erratum regarding missing Declaration of Competing Interest statements in previously published articles.

[This corrects the article DOI: 10.1016/j.gore.2018.03.007.][This corrects the article DOI: 10.1016/j.gore.2019.03.005.][This corrects the article DOI: 10.1016/j.gore.2020.100554.][This corrects the article DOI: 10.1016/j.gore.2019.07.002.][This corrects the article DOI: 10.1016/j.gore.2020.100581.][This corrects the article DOI: 10.1016/j.gore.2018.07.001.][This corrects the article DOI: 10.1016/j.gore.2018.10.009.][This corrects the article DOI: 10.1016/j.gore.2019.03.017.][This corrects the article DOI: 10.1016/j.gore.2019.07.005.][This corrects the article DOI: 10.1016/j.gore.2019.07.010.][This corrects the article DOI: 10.1016/j.gore.2018.05.008.][This corrects the article DOI: 10.1016/j.gore.2018.05.012.][This corrects the article DOI: 10.1016/j.gore.2018.08.004.][This corrects the article DOI: 10.1016/j.gore.2020.100597.][This corrects the article DOI: 10.1016/j.gore.2020.100598.].