[Alexander] ...[etc.].

MLA

Seifrit, et al. [Alexander] ...[etc.]. [Austria or Southern Germany], [between 1400 and 1475]

APA

Seifrit, Gross, E., Wyle, N., Schwent, H., Pius, Leo, Boccaccio, G., Eyb, A., Gruber, P. & Piaristenkollegium St. Thekla auf der Wieden (Vienna). (1400). [Alexander] ...[etc.]. [Austria or Southern Germany].

Chicago

Seifrit, Erhart Gross, Niklas von Wyle, Hans Schwent, Pius, Leo and Giovanni Boccaccio, et al. [Alexander] ...[etc.]. Translated by Niklas von Wyle. [Austria or Southern Germany], [between 1400 and 1475]