You must reference the ORIGINAL SOURCE DOCUMENT (aka Form 10-K, etc.) for every figure you obtain. The database suggestions provided herein are useful tools for extracting and analyzing data from source documents, but you must always be sure you understand, and can cite, the ultimate source.
As well as these databases, don't forget the company's own website. There is often an 'Investor Relations' section, which will provide access to potentially useful information.
"...overview of industry, unique attributes and how each company fits into this industry sector... ...key relevant financial data"
"economics..." ...factors that may impact the company's/companies'/industry's profitability... "...pricing, product differentiation, etc."