фактопедия

"Strata" is a science fiction novel by Terry Pratchett. Published in 1981, it is one of Pratchett's first novels and one of the few purely science fiction novels he wrote, along with "The Dark Side of the Sun" and "The Nome Trilogy".

Ну...
Трилогия про гномиков -- это 1989-1991, вообще-то, и никоим образом не фантастика. В общем, "не 'Волгу', а сто рублей".