Английский словарь американских идиом - says who

or says you {v. phr.}, {slang} I don't believe or accept that. - An expression of rebuff often used to make fun of someone or oppose him. * /"I am the strongest boy on the block." "Says you./" * /"That brook is full of trout." "Says who? I never saw anybody catch trout there."/ * /"You can't take Mary to the party - she's my girl." "Says who?"/