Dilworth, S. J.
Gogyan, S.
Kutzarova, Denka
Schlumprecht, Th.
Funding for this research was provided by:
Directorate for Mathematical and Physical Sciences (1160633)
Directorate for Mathematical and Physical Sciences (1464713)
Directorate for Mathematical and Physical Sciences (1361461)
Bulgarian National Science Fund (DFNI/I02/10)
Article History
Received: 28 October 2015
Accepted: 19 March 2016
First Online: 1 April 2016