The treatment of a secondary alkyl halide like 2-fluorobutane with a base such as alcoholic potassium hydroxide is a standard textbook example of a base-promoted elimination reaction (dehydrohalogenation) yielding alkenes, which is a matter of established chemical fact requiring no citation.
The claim is a standard, universally accepted undergraduate chemistry fact regarding base-induced elimination reactions of alkyl halides to form alkenes. None of the retrieved papers provide direct experimental evidence bearing on this specific reaction, but the claim itself is fundamentally sound chemical knowledge.