https://fenix.ist.utl.pt/researcher/resultPublications/showPublication.do?resultId=245998&contentContextPath_PATH=/curriculum/investigacao&_request_checksum_=f9297e61985aa4465cfa7820f0cdb3ab62544efb , Jorge Manuel Amaro Henriques Loureiro , IST Press, 2008, http://www.istpress.ist.utl.pt/lfisicarelativista.htm (https://fenix.ist.utl.pt/researcher/publications/bibtexManagement.do?method=exportPublicationToBibtex&publicationId=245998&contentContextPath_PATH=/curriculum/investigacao&_request_checksum_=4988a080e3c6ea1265cd36cc89e3151cf1bd73c4 )