What paper size are the English versions supposed to be on?
On Debian testing, the packages texlive-lang-czechslovak and
texlive-lang-polish will let you generate the cs-* and sk-* pdfs.
+(You may need texlive-lang-cyrillic, texlive-lang-german for others.)
The Makefile rules did not work for me, I had to use something like:
csplain -output-format=pdf cs-refcard