# Optimal control approach of a mathematical modeling with multiple delays of the negative impact of delays in applying preventive precautions against the spread of the COVID-19 pandemic with a case study of Brazil and cost-effectiveness

> Research article (Chaos Solitons & Fractals, 2020) · cited 42× · AI/ML

**Wikidata**: [openalex:W3095218909](https://www.wikidata.org/wiki/openalex:W3095218909)  
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