It's easy to cite LitCharts for use in academic papers and reports.
MLA
Rainbow, Sophie. "The Red-Headed League." LitCharts. LitCharts LLC, 6 Sep 2018. Web. 20 Sep 2020.
Chicago
Rainbow, Sophie. "The Red-Headed League." LitCharts LLC, September 6, 2018. Retrieved September 20, 2020. https://www.litcharts.com/lit/the-red-headed-league.