https://ecommercenews.eu/over-500-million-ecommerce-users-in-europe-in-2021/
https://www.statista.com/forecasts/715663/e-commerce-revenue-forecast-in-Europe
https://www.statista.com/forecasts/715663/e-commerce-revenue-forecast-in-Europe
https://wearesocial-net.s3.amazonaws.com/wp-content/uploads/2018/01/DIGITAL-IN-2018-021-AVERAGE-ECOMMERCE-REVENUES-PER-USER-V1.00.png
https://ecommercenews.eu/ecommerce-in-europe/ecommerce-the-netherlands/
https://wearesocial-net.s3.amazonaws.com/wp-content/uploads/2018/01/DIGITAL-IN-2018-021-AVERAGE-ECOMMERCE-REVENUES-PER-USER-V1.00.png
https://www.jpmorgan.com/europe/merchant-services/insights/reports/poland
https://www.statista.com/study/38799/e-commerce-in-the-netherlands-statista-dossier/;SE-https://www.statista.com/study/36980/e-commerce-in-sweden-statista-dossier/;PL-https://www.statista.com/study/38799/e-commerce-in-the-netherlands-statista-dossier/
https://zhuanlan.zhihu.com/p/348532487
https://www.kuajingyan.com/article/10767