Guido of Arezzo

MLA style (see MLA Style Manual and Guide to Scholarly Publishing, 3rd Ed.)

. "Guido of Arezzo." The Canterbury Dictionary of Hymnology. Canterbury Press. Web. 21 Jul. 2019.<http://www.hymnology.co.uk/g/guido-of-arezzo>.

Chicago style (see The Chicago Manual of Style, 16th Ed.)

. "Guido of Arezzo." The Canterbury Dictionary of Hymnology. Canterbury Press, accessed July 21, 2019, http://www.hymnology.co.uk/g/guido-of-arezzo.