De descriptione terre s[an]c[t]e ... [etc.].

MLA

Burchard, et al. De descriptione terre s[an]c[t]e ... [etc.]. [Italy], [between 1350 and 1450]

APA

Burchard, Brocardus, Peregrinus & Sanudo, M. (1350). De descriptione terre s[an]c[t]e ... [etc.]. [Italy].

Chicago

Burchard, Brocardus, Peregrinus and Marino Sanudo. De descriptione terre s[an]c[t]e ... [etc.]. [Italy], [between 1350 and 1450]