Submitted on: 26 October 2015.
Revised on: 07 February 2016.
Accepted on: 21 March 2016.
___________________Annals of Combinatorics---SPRINGER BASEL AG
Submitted on: 17 May 2005.
Revised on: 26 August 2005.
Accepted on: 05 September 2005.
___________________Annals of Combinatorics---SPRINGER BASEL AG
Submitted on: 29 April 2010.
Revised on: 30 July 2010.
Accepted on: 04 September 2010.
___________________Annals of Combinatorics---SPRINGER BASEL AG
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http://reply.papertrans.cn/1/18/1770/1770-35.png
Submitted on: 18 March 2007.
Revised on: 07 May 2007.
Accepted on: 01 July 2007.
___________________Annals of Combinatorics---SPRINGER BASEL AG