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Submitted on: 28 December 1998.
Revised on: 25 February 1999.
Accepted on: 24 April 1999.
___________________BRITTONIA---SPRINGER
Submitted on: 29 March 2012.
Revised on: 23 July 2012.
Accepted on: 14 September 2012.
___________________BRITTONIA---SPRINGER
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Submitted on: 20 October 2019.
Revised on: 16 November 2019.
Accepted on: 27 December 2019.
___________________BRITTONIA---SPRINGER
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