Click here, for the category page with a list of studies, and here for the project page.
Ha! If I hadn't been so verbose and taken so long to type my answer, I might have seen that you'd already answered.
Heh, it happens and sometimes what one misses in a quick answer is provided by someone who takes longer with their own answer.
If you are looking for the One Name Studies project, it is here:
Project:One Name Studies
You can find a listing of all projects from your profile page. Click Find > Projects. An alphabetical listing of WikiTree projects comes up.
If you are looking for a list of current One Name Studies, it is here:
Category:One Name Studies