9Almeida, H. , Campello, M. , and Weisbach, M. The cash flow sensitivity of cash. Journal of Finance, 2004 (59) : 1777 - 1804.
10Areharya, V. V. , Almeida, H. , and Campello, M. Is cash negative debt? A hedging perspective on corporate financial policies. Journal of Financial Intermediation, 2007 ( 16): 515- 554.