Dictionaries, encyclopedias, guides, and handbooks are great sources of background information and can be valuable tools when you start your research project.
The Handbook of International Financial Terms by For more in-depth background information on finance and investment topics, consult one of these encyclopedias:
Principles of Business: Finance
Capital Markets: Evolution of the Financial EcosystemLearn more about your particular topic (e.g., ETFs or Private Equity) by consulting one or more of these specialized guides and handbooks.
The Oxford Handbook of Private Equity by 
The Oxford Handbook of Credit Derivatives by 
