Publisher: Charity Navigator
Cumulative list of organizations described in section 170 (c) of the Internal Revenue Code of 1954.
Publisher: U.S. Internal Revenue Service
Archived in HathiTrust repository.
Publisher: Foundation Center
Give.org: BBB Wise Giving Alliance
Publisher: Better Business Bureau
For Charities and Donors.
GuideStar: Trusted Nonprofit Information and Donor's Guide
Publisher: Philanthropic Research, Inc.
National Center for Charitable Statistics
Publisher: National Center for Charitable Statistics
Nonprofit Startup Guide
Publisher: Harbor Business Compliance
USA.gov for Nonprofits