P2#, M.Dragoun — Duplexy,
Bila vsepromena,
Mat Kralivskou battery,
Cykly tahu The origin and description of Duplex term in a help mate with a big number of examples in chess problems of different types
Price:7€ each
About order of the books, contact with Kopyl Valery. His contact details can be found on the page "Contacts".