BALCERZAK, Andrzej. “Ultrasonic Measurements of Aqueous Solutions of [ampersand]beta;-Cyclodextrin With Alkyl Pyridinium Bromides”. Archives of Acoustics, vol. 33, no. 4, Jan. 2008, pp. 627–641, https://acoustics3.ippt.pan.pl/index.php/aa/article/view/560.