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. 2021 Sep 17;9:130072–130093. doi: 10.1109/ACCESS.2021.3113812

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This work is licensed under a Creative Commons Attribution 4.0 License. For more information, see https://creativecommons.org/licenses/by/4.0/

This work is licensed under a Creative Commons Attribution 4.0 License. For more information, see https://creativecommons.org/licenses/by/4.0/

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FIGURE 2. — Number of publications by country (using the keywords optimization and COVID-19).