Subject: Theology
Author of work: Gregorius I
Title: Moralia
Subject: Music
Title: Polyphonic music
Subject: Canon Law
Author of work: Guido de Baysio
Title: Comment. in Sextum librum Decretalium
Subject: Canon Law
Author of work: Gratianus
Title: Decretum
Subject: Civil Law
Author of work: Justinianus
Title: Digestum vetus
Subject: Theology
Title: theological questions
Subject: Natural philosophy
Title: Natural philosophy
Subject: Civil Law
Author of work: Justinianus
Title: Digestum vetus
Subject: Civil Law
Author of work: Justinianus
Title: Digestum vetus
Subject: Documentary
Title: Registrum Johannis de Gaunt