After 1948, his health deteriorating, Bunin concentrated upon writing memoirs and a book on Anton Chekhov. He was aided by his wife, who, along with Zurov, completed the work after Bunin's death and saw to its publication in New York in 1955. In English translation it was entitled "About Chekhov: The Unfinished Symphony". Bunin also revised a number of stories for publication in new collections, spent considerable time looking through his papers and annotated his collected works for a definitive edition. In 1951 Bunin was elected the first ever hononary International PEN member, representing the community of writers in exile. According to A.J. Heywood, one major event of Bunin's last years was his quarrel in 1948 with Maria Tsetlina and Boris Zaitsev, following the decision by the Union of Russian Writers and Journalists in France to expel holders of Soviet passports from its membership. Bunin responded by resigning from the Union. The writer's last years were marred by bitterness, disillusionment and ill-health; he was suffering from asthma, bronchitis and chronic pneumonia.