Table:
| (IN MILLIONS) | 2019 | 2018 | 2017 |
| --- | --- | --- | --- |
| Net cash from operating activities | $1,066 | $1,058 | $1,310 |
| Cash and short-term marketable securities | $454 | $524 | $656 |
| Revolving credit facility | $850 | $850 | $575 |
Paragraphs:
Liquidity and Capital Resources
Cash flows from operations provided a source of funds of $1,066 million, $1,058 million and $1,310 million during the years ended December 31, 2019, 2018 and 2017, respectively. This increase was driven primarily by lower employee annual incentive payments, lower retailer investments and lower restructuring payments, partially offset by working capital timing and higher interest and tax payments during the year ended December 31, 2019.
We provide for additional liquidity through several sources, including maintaining an adequate cash balance, access to global funding sources and a committed revolving credit facility. The following table provides a summary of the major sources of liquidity for the years ended December 31, 2019, 2018 and 2017:
Of the $454 million in cash and cash equivalents at December 31, 2019, approximately $383 million was held in jurisdictions outside the U.S. We regularly review the amount of cash and cash equivalents held outside of the U.S. to determine the amounts necessary to fund the current operations of our foreign operations and their growth initiatives and amounts needed to service our U.S. indebtedness and related obligations.
Question:
What are the additional sources for additional liquidity?