[EM] Condorcet incompatibility proofs

[James Green-Armytage]

Hi folks,
	Looking for help again! Does anyone know where I can find the earliest
proof that Condorcet efficiency is incompatible with consistency?
Basically, I'm just looking for the most appropriate source to cite when
mentioning the impossibility. 
	I'm also not sure who to cite for Condorcet being incompatible with
later-no-help and later-no-harm. Is it Woodall in Voting Matters, May 1996?

thanks so much!
James