Analysis of information sources in references of the Wikipedia article "Khoa học viễn tưởng nặng" in Vietnamese language version.
hard science fiction... the term was first used by P. Schuyler Miller in 1957
Soft science fiction, probably a back-formation from Hard Science Fiction)
Earliest cite: P. Schuyler Miller in Astounding Science Fiction... he called A Fall of Moondust "hard" science fiction
Earliest cite: P. Schuyler Miller in Astounding Science Fiction... he called A Fall of Moondust "hard" science fiction