In 1983, at the request of a referee, I added to a paper of mine a proof that (under certain hypotheses which need not detain us here) a certain norm could be given as a certain resultant. Since then I have found that the same theorem had already been published by (at least) half-a-dozen authors going back to Cebotarev in 1936, none of them citing any of their predecessors.

Oh what the heck. It's a nice result, and not all that hard to state. Let $A$ be a commutative ring with unity. Let $f$ and $g$ be in $A[x]$, with $f$ monic. Let $B=A[x]/(f)$. Then the resultant of $f$ and $g$ equals the norm from $B$ to $A$ of the class of $g$ in $B$.