by donato bini, bob jantzen, andrea geralico and collaborators for ICRA (Remo Ruffini)
Original articles in Italian:
https://archive.org/details/collectedpapersn007155mbp/page/n11/mode/2up?view=theater
https://archive.org/details/collectedpapersn007155mbp/page/n1113/mode/2up