It's easy to cite LitCharts for use in academic papers and reports.
MLA
O'Dwyer, Deirdre. "The Adventures of Tom Sawyer." LitCharts. LitCharts LLC, 22 Jul 2013. Web. 22 Jan 2021.
Chicago
O'Dwyer, Deirdre. "The Adventures of Tom Sawyer." LitCharts LLC, July 22, 2013. Retrieved January 22, 2021. https://www.litcharts.com/lit/the-adventures-of-tom-sawyer.