The inertia of Hermitian tridiagonal block matrices. da Fonseca, C.M. — 2004 JIPAM. Journal of Inequalities in Pure & Applied Mathematics [electronic only]
On a conjecture regarding characteristic polynomial of a matrix pair. da Fonseca, C.M. — 2005 ELA. The Electronic Journal of Linear Algebra [electronic only]
A lower bound for the number of distinct eigenvalues of some real symmetric matrices. Da Fonseca, C.M. — 2010 ELA. The Electronic Journal of Linear Algebra [electronic only]
A note on the spectra of tridiagonal matrices. da Fonseca, C.M.; Petronilho, J. — 2004 International Journal of Mathematics and Mathematical Sciences