What might be the best link to drop on someone to prove to them that being transgender is scientifically valid?

The majority of transphobes I bump into online seem to simply be magnificently ignorant - they do not understand that science has validated our existence. I feel like the first step in 'deradicalizing' a transphobe is to get them to understand the scientific validity behind gender.

However there's so many links out there - would anyone have any suggestions on the best, most scientific link(s) I could drop on someone to prove to them that science is on our side? I want something that they cannot refute logically and so are forced to confront emotionally.

Thanks! :)