Ivanov, Stefan, Ivan Minchev, and Dimiter Vassilev. “The Optimal Constant in the L<sup>2</Sup> Folland-Stein Inequality on the Quaternionic Heisenberg Group”. ANNALI SCUOLA NORMALE SUPERIORE - CLASSE DI SCIENZE 11, no. 3 (September 24, 2012): 635-662. Accessed February 20, 2026. https://journals.sns.it/index.php/annaliscienze/article/view/275.