Wolny dostęp do artykułu, brak informacji o licencji. Received: November 30, 2018 ; Accepted: June 17, 2019 ; Prepublished online: August 1, 2019 ; Published: October 30, 2019. The contribution of Ch. Li and A. Witkowski has been performed within the frame of topical subsidy of the Polish Ministry of Science and Higher Education |