There's a lot about the gender gap, in terms of Wikipedia projects, published research, and initiatives. 

What resource (on wiki or not) do you think gives the best  overview / summary / introduction to the gender gap on Wikipedia? What is the best source you know of, that could give someone a solid orientation on the issue?

Thanks for all the feedback; it's super helpful, especially when resources get mentioned that I didn't have on my radar.

Mary Mark Ockerbloom