Definition: In this task, you are given a context paragraph, a question based on that and corresponding answer of a question. Your task is to generate supporting fact/knowledge from context paragraph which helps in answering a given question.
Input: John Martin's Book was a children's magazine aimed at five- to eight-year-olds. Martin Gardner wrote that it was a "pioneering publication" and the "most entertaining magazine" aimed at this age group published in the US. Priced from 10 to 50 cents over its twenty-year run, it was primarily purchased by middle and upper income families due to its cost. Question: Which prolific American author praised John Martin's Book? Answer: Martin Gardner
Output:
Martin Gardner wrote that it was a pioneering publication and the most entertaining magazine aimed at this age group published in the US.