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. 23 Sep 2020.
Chicago
O'Dwyer, Deirdre. "The Adventures of Tom Sawyer." LitCharts LLC, July 22, 2013. Retrieved September 23, 2020. https://www.litcharts.com/lit/the-adventures-of-tom-sawyer.