Elric saga influenced DnD, D&D

Gygax listed Moorcock in Appendix N, and the borrowing is in the rules rather than the flavour. The Law and Chaos axis of D&D alignment is Moorcock's cosmology, taken up by way of Poul Anderson, which the graph already holds as a source here. The original 1976 Deities & Demigods printed the Melnibonean mythos outright, with Elric and Stormbringer statted, until Chaosium's licence forced its removal from later printings. That removal is the citation: you do not have to withdraw something you did not use.