"Almost none of his works have been translated into English; the only exception is the short story Wyjątkowo trudny teren ("Particularly Difficult Territory") that Zajdel wrote for the English language Tales from the Planet Earth anthology edited by Frederik Pohl and Elizabeth Anne Hull." -- https://en.wikipedia.org/wiki/Janusz_Zajdel

Only managed to find that one, offline page. You can click an arrow pointing up (/abc.htm) on this weird google translate/archive.org contraption to reach index.