IVANOVA-KARATOPRAKLIEVA, I. Infinitesimal bendings with sliding of higher order of rotational surfaces. Ann. Sofia Univ. Fac. Math. and Inf., [S. l.], v. 84, p. 69–82, 1993. Disponível em: https://admin.uni-sofia.bg/index.php/fmi/article/view/470. Acesso em: 16 jan. 2025.