JANUŠAUSKAITĖ, Nijolė. The problem of the second variation of the discrete generalized Mayer form’s functional. Lietuvos matematikos rinkinys, [S. l.], v. 38, n. II, p. 433–437 , 1998. DOI: 10.15388/LMD.1998.37950. Disponível em: https://journals.vu.lt./LMR/article/view/37950. Acesso em: 19 apr. 2025.