Submitted on: 11 March 2018.
Revised on: 02 June 2018.
Accepted on: 23 June 2018.
___________________Electronic Journal of Differential Equations
Submitted on: 28 September 2022.
Revised on: 25 October 2022.
Accepted on: 17 November 2022.
___________________Electronic Journal of Differential Equations
Submitted on: 03 November 2004.
Revised on: 11 February 2005.
Accepted on: 06 March 2005.
___________________Electronic Journal of Differential Equations
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Submitted on: 05 September 1998.
Revised on: 22 November 1998.
Accepted on: 16 January 1999.
___________________Electronic Journal of Differential Equations
Submitted on: 09 May 2005.
Revised on: 25 June 2005.
Accepted on: 23 August 2005.
___________________Electronic Journal of Differential Equations
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Submitted on: 08 July 2013.
Revised on: 13 September 2013.
Accepted on: 05 October 2013.
___________________Electronic Journal of Differential Equations
Submitted on: 01 May 2002.
Revised on: 25 July 2002.
Accepted on: 14 August 2002.
___________________Electronic Journal of Differential Equations