Konovalova, Zhanna. “The Transformation of the Frontier Concept In Election Campaign Speeches and Inaugural Addresses of American Presidents (Based on Speeches by B. Obama, D. Trump, and J. Biden)”. Journal of Frontier Studies 10, no. 2 (April 21, 2025): 219-239. Accessed June 21, 2025. https://www.jfs.today/index.php/jfs/article/view/658.