I want to know the answer to the following question:
The shadow banking system could not provide funds to mortgage firms and other corporations without the ability to obtain which funds?
All the background I'm provided with is that "Economist Paul Krugman and U.S. Treasury Secretary Timothy Geithner explain the credit crisis via the implosion of the shadow banking system, which had grown to nearly equal the importance of the traditional commercial banking sector as described above.". Is that enough to answer the question?