John Russell Fearn (1908–1960) was a British author and one of the first British writers to appear in American pulp science fiction magazines. A prolific author, he published his novels also as Vargo Statten and with various pseudonyms such as Thornton Ayre, Polton Cross, Geoffrey Armstrong, John Cotton, Dennis Clive, Ephriam Winiki, Astron Del Martia and others. "Mathematica Plus' is his sequel to "Mathematica".