Columbia subject headings:
Porfyrius, P. Optatianus, active 325--Congresses.
Harvard subject headings:
Latin language--Figures of speech--Congresses.
Latin poetry--History and criticism.
Metaphor--Congresses.
Porfyrius, P. Optatianus, active 325--Criticism, Textual--Congresses.
Symbolism in literature--Congresses.
Princeton subject headings:
Porfyrius, P. Optatianus, active 325--Congresses.