As far as reputable sources, you will find everything you need at www.cirp.org
-- it has the most extensive collection of peer-reviewed papers on circ, all from medical journals.
Also, you don't even have to go to the medical journals. Just look at all the statements from medical organizations such as the AAP, which have reviewed literally hundreds of studies, and still found no reason to circ.
But here's a thought -- your husband is essentially the plaintiff or prosecutor, wanting to change the status quo (which is an intact baby who keeps all the parts he was born with). He is advocating for surgery, and as the plaintiff, he should bear the burden of proof that the surgery is necessary. You need to make HIM do the research and prove to YOU that the surgery is necessary -- and only medical reasons will cut it, because cosmetic surgery on a baby is simply not worth the real and known risks (bleeding, infection, penile amputation, meatal stenosis, all the way up to death).
Tell him that if this surgery is so important to him, he needs to research it and then carry his burden of proof to demonstrate -- beyond a reasonable doubt, to borrow a standard from the criminal side. Hearsay testimony (i.e., "my cousin's uncle's mailman HAD to have a circ, or was teased) carries very little weight -- he has to do the medical research to prove his case, that circumcision is in his son's best medical interests.