Yes there are and he cited them in his memo. And the studies have been replicated in studies that draw participants from as many as 51 countries and find similar results across different cultures [1].

If you think his presentation of this data is ineffective, then the productive thing to do is offer a reasoned refutation. Not exaggerate (to be generous, I'm more inclined to call these fabrications) and write that he claimed "women are genetically worse leaders" and "naturally worse negotiators."

1. https://psycnet.apa.org/record/2005-13299-011