question: What historian commented that the events involving Frédéric 's friend in Poland contributed to his maturing ?
answer: Zdzisław Jachimecki
turker_answer: Historian Zdzisław Jachimecki commented that the events involving Frédéric 's friend in Poland contributed to his maturing .
rule-based: Zdzisław Jachimecki commented that the events involving Frédéric 's friend in Poland contributed to his maturing .