She [Echidna] was the mother of Chimaera who breathed raging fire,  a creature fearful, great, swift footed and strong, who had three heads, one of a grim-eyed lion, another of a goat, and another of a snake, a fierce dragon; in her forepart she was a lion; in her hinderpart, a dragon; and in her middle, a goat, breathing forth a fearful blast of blazing fire.  Her did Pegasus and noble Bellerophon slay (original Greek).
Hes fr 43a MW (R. Merkelbach and M.L. West, Fragmenta Hesiodea , pp. 27-31)
Bellerophon by Eurynome, daughter of Nysus (original Latin).
ApB (Apollodoros, Bibliotheke [Library]) 1.9.3:
And Sisyphus, son of Aeolus, founded Ephyra, which is now called Corinth, and married Merope, daughter of Atlas. They had a son Glaucus, who had by Eurymede a son Bellerophon, who slew the fire breathing Chimera (original Greek).
∑T Il (Scholia for Homer, Iliad) 6.191 (Scholia Graeca in Homeri Iliadem, ed. W. Dindorf, vol. 5 , p. 214)
Hes fr 129 MW (R. Merkelbach and M.L. West, Fragmenta Hesiodea , pp. 62-63)
Ol (Pindar, Olympian) 13.63-92:
Bellerophon… once suffered greatly when beside the spring he wanted to harness Pegasus, the son of the snake-entwined Gorgon;  until the maiden Pallas brought to him a bridle with golden cheek-pieces. The dream suddenly became waking reality, and she spoke: “Are you sleeping, king, son of Aeolus? Come, take this charm for the horse; and, sacrificing a white bull, show it to your ancestor, Poseidon the Horse-Tamer.”  The goddess of the dark aegis seemed to say such words to him as he slumbered in the darkness, and he leapt straight up to his feet. He seized the marvellous thing that lay beside him, and gladly went to the seer of the land,  and he told the son of Coeranus the whole story: how, at the seer’s bidding, he had gone to sleep for the night on the altar of the goddess, and how the daughter herself of Zeus whose spear is the thunderbolt had given him the spirit-subduing gold. The seer told him to obey the dream with all speed;  and, when he sacrificed a strong-footed bull to the widely powerful holder of the earth, straightaway to dedicate an altar to Athena, goddess of horses. The power of the gods accomplishes as a light achievement what is contrary to oaths and expectations. And so mighty Bellerophon eagerly  stretched the gentle charmed bridle around its jaws and caught the winged horse. Mounted on its back and armored in bronze, at once he began to play with weapons. And with Pegasus, from the chilly bosom of the lonely air, he once attacked the Amazons, the female army of archers,  and he killed the fire-breathing Chimaera, and the Solymi. I shall pass over his death in silence; but Pegasus has found his shelter in the ancient stables of Zeus in Olympus (original Greek).
Is (Pindar, Isthmian) 7.43-48:
If a man looks to things far away, he is too short to reach the bronze-floored home of the gods; winged Pegasus threw his master Bellerophon, who wanted to go to the dwelling-places of heaven and the company of Zeus (original Greek).
But when even Bellerophon came to be hated of all the gods, then verily he wandered alone over the Aleian plain, devouring his own soul, and shunning the paths of men (original Greek).
Cited in note 29 for p. 314: Scholia B for Il (Homer, Iliad) 6.200 (Scholia in Homeri Iliadem, ed. I. Bekker, vol. 1 , p. 175)
Sophokles, Iobates (Tragicorum Graecorum Fragmenta, ed. A. Nauck [2nd ed. 1889], pp. 194-195)