 His first novel, "Lalande 21185", appeared in 1966, a year after his first short-story anthology, and was geared toward young adults.His first serious science-fiction novel was a "first contact"-type SF mystery, ' (Right of Return, 1975); but it was his novels of the late 1970s and early 1980s – "Cylinder van Troffa" (Van Troff's Cylinder, 1980); "Limes inferior" (The Lower Limit, 1982); "Cała prawda o planecie Ksi" (The Whole Truth about Planet Xi, 1983); ' (Out of the Shadows, 1983); and "Paradyzja" (Paradise