WESOŁOWSKI, Z. O Prędkościach Fali Kulistej w Izotropowym Materiale Sprężystym. Engineering Transactions, [S. l.], v. 23, n. 2, p. 325–340, 1975. Disponível em: https://et.ippt.gov.pl/index.php/et/article/view/2362. Acesso em: 19 mar. 2026.