Some citation databases include a field for grants that have funded the research reported by the article. You can search for a sponsor to see the types of projects they've funded in the past. Or search on your topic and look for this field to identify potential sources of funding.
The NIH guide to acronyms can translate which agencies funded the research. The grant number from these fields can be entered into a funded research database (such as NIH RePORTER) to find out more about the original grant application.
For example, searching for articles about maternal caregivers finds this record whose Grant Information field shows it was funded by grants from the National Institute of Nursing Research, the ONS Foundation, and the American Brain Tumor Association.
Find additional literature on grants and funding in PubMed. Use this saved search strategy as a base and add your own keywords for your particular research or interest area:
(("Fund Raising"[Mesh] OR "Financing, Organized"[Mesh:noexp] OR "Financing, Government"[Mesh:noexp]) OR ("Biomedical Research/economics"[Mesh]) OR ("Financial Support"[Mesh]) OR (("Epidemiologic Research Design"[Mesh]) AND ("economics"[MeSH Subheading])) OR ("Research Personnel/economics"[Mesh]) OR ("Research/economics"[Mesh]) OR ("Ethics Committees/economics"[Mesh])) OR ("grant*"[title] OR "fund"[title] OR "funds"[title] OR "funding"[Title])
Here are the five most recent articles from this search: