A note lower bounds for the Estrada index. - Jonnathan Rodríguez; Juan L. Aguayo; Juan R. Carmona; Akbar Jahanbani (Discret. Math., 2021)

An (increasing) sequence of lower bounds for the spectral radius and energy of digraphs. - Hilal A. Ganie; Juan R. Carmona (Discret. Math., 2023)

Some bounds for the Aα-spectral radius of a digraph. - Juan R. Carmona; Hilal A. Ganie (Discret. Math. Algorithms Appl., 2024)