Columbia subject headings:
Invertebrates--Physiology--Congresses.
Photoreceptors--Congresses.
Vision--Congresses.
Harvard subject headings:
Invertebrates--Physiology--Congresses
Photoreceptors--Congresses
Vision--Congresses
Princeton subject headings:
Invertebrates--Physiology--Congresses.
Photoreceptors--Congresses.
Vision--Congresses.