Links

Modern edition of Requiem in the Choral Public Domain Library
Photographs of a copy of Requiem (Acervo Musical do Cabido Metropolitano do Rio de Janeiro)
Biography and works list of Marcos Portugal (by David Cranmer and António Jorge Marques)
“D. João VI and Marcos Portugal: The Brazilian Period”, by António Jorge Marques (Music and Culture in the Imperial Court of João VI in Rio de Janeiro, University of Texas, 2005)