Submitted on: 22 April 2015.
Revised on: 16 May 2015.
Accepted on: 22 May 2015.
Quaestiones Mathematicae---TAYLOR & FRANCIS LTD
Submitted on: 06 August 2000.
Revised on: 21 August 2000.
Accepted on: 27 August 2000.
Quaestiones Mathematicae
Submitted on: 09 June 1998.
Revised on: 20 July 1998.
Accepted on: 01 August 1998.
Quaestiones Mathematicae
Submitted on: 18 October 2005.
Revised on: 26 October 2005.
Accepted on: 08 November 2005.
Quaestiones Mathematicae---TAYLOR & FRANCIS LTD
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Submitted on: 10 July 2016.
Revised on: 13 August 2016.
Accepted on: 03 September 2016.
Quaestiones Mathematicae---TAYLOR & FRANCIS LTD