Vronskii, B. M. “On Small Oscillations of a Compressible Stratified Liquid”.
Ukrains’kyi Matematychnyi Zhurnal
58, no. 12 (December 25, 2006): 1614–1623. Accessed April 11, 2025.
https://umj.imath.kiev.ua/index.php/umj/article/view/3559
.