Nonprofit Quarterly (the ultimate, practitioner-focused publication of the sector!) is making available its special issue, "A Case for Nonprofit Infrastructure."
You need to register (free) for the site to access the set of articles. Once you've done that, you'll be able to click on the link taking you to the issue table of contents. Note that there are links to PDF versions at the top of each article page.
To access the issue, click here.