This source names Cronus directly: "tradition Demeter is a daughter of Cronus and Rhea and mother, by her brother Zeus, of Persephone, whose abduction by Hades is the central episode of Demeter's own myth."
Source The Homeric HymnsAnonymous; ascribed in antiquity to Homer
This source names Demeter directly: "collection API record for "Figurine of Demeter with Pig," a terracotta figurine from Greece, Athens, 400s BCE."
Source Figurine of Demeter with Pig, accession 1926.521 (Cleveland Museum of Art)
This source names Demeter directly: "further deities, including Hestia, Demeter, Leto, Themis, Eileithyia and Tethys, that neither source read for this record independently confirmed against the vase's own inscriptions."
Source Florence 4209, the Francois Vase (Perseus Project Art and Archaeology Artifact Browser)
This source names Demeter directly: "and confirming the depicted figures as Demeter, Triptolemus and Persephone."
Source Great Eleusinian Relief, Wikidata (Q16330627)
This source names Demeter directly: "and dimensions, its iconography of Demeter, Triptolemus and Persephone, and the Roman-era copies including fragments at the Metropolitan Museum of Art."
Source Great Eleusinian Relief, Wikipedia
Hades, Deities This source names Hades directly: "of Persephone, whose abduction by Hades is the central episode of Demeter's own myth."
Source The Homeric HymnsAnonymous; ascribed in antiquity to Homer
This source names Demeter directly: "an initiate owed the priestess of Demeter and the Eumolpidai and Kerykes priestly families."
Source Regulations Concerning the Eleusinian Mysteries (AIUK 4.2 no. 1, Attic Inscriptions Online)Stephen Lambert and Robin Osborne (translators)
Rhea, Deities This source names Rhea directly: "Demeter is a daughter of Cronus and Rhea and mother, by her brother Zeus, of Persephone, whose abduction by Hades is the central episode of Demeter's own myth."
Source The Homeric HymnsAnonymous; ascribed in antiquity to Homer
Zeus, Deities This source names Zeus directly: "and Rhea and mother, by her brother Zeus, of Persephone, whose abduction by Hades is the central episode of Demeter's own myth."
Source The Homeric HymnsAnonymous; ascribed in antiquity to Homer