“Do you have a cite to an authoritative Merck study that demonstrates no connection to retardation for this specific vaccine?”
Is there a study that shows that there are no flying pink unicorns? No. If you want to say there are flying pink unicorns, you have to find a flying pink unicorn.
I've done neither. In fact, I'm using Merck's own study published on a commercial website just so the gub'mnt didn't take the opportunity to edit out the parts "they" don't like. With a Stalinist battleaxe like Sibelius in charge of such things these days you really can't be too careful ~