Table:
| ($ in billions) |  |  |  |
| --- | --- | --- | --- |
|  | 2019 | 2018 | 2017 |
| Net cash operating activities | $14.8 | $15.2 | $16.7 |
| Cash, restricted cash and short-term marketable securities | $ 9.0 | $12.2 | $12.8 |
| credit facilities | $15.3 | $15.3 | $15.3 |
Paragraphs:
The company has consistently generated strong cash flow from operations, providing a source of funds ranging between $14.8 billion and $16.7 billion per year over the past three years.
The company provides for additional liquidity through several sources: maintaining an adequate cash balance, access to global funding sources, committed global credit facilities and other committed and uncommitted lines of credit worldwide.
The following table provides a summary of the major sources of liquidity for the years ended December 31, 2017 through 2019.
Question:
What are the sources of additional liquidity?
Answer: maintaining an adequate cash balance, access to global funding sources, committed global credit facilities and other committed and uncommitted lines of credit worldwide.