Invariance and Set-Theoretical Operations in First Order Structures. - Alexandre A. M. Rodrigues; Ricardo C. Miranda Filho; Edelcio Gonçalves de Souza (Reports Math. Log., 2006)

Definability in infinitary languages and invariance by automorphims. - Alexandre A. M. Rodrigues; Ricardo C. Miranda Filho; Edelcio Gonçalves de Souza (Reports Math. Log., 2010)