original: His travel writings and his extensive diaries and correspondence have also been published.
simplifications: His travel writings and his many diaries and letters have also been published. His collection of diaries and letters were published. His travel writings, diaries and letters have also been published. His travel writings and long diaries and letters have also been published. His writings, diaries and correspondence have all been published. His travel writings, diaries, and letters have also been published. His travel writings, diaries, and conversations have also been published. His travel writings, extensive diaries and correspondence have also been published. His travel writings and his complete diaries and letters have also been printed. His travel writings, extensive diaries, and correspondence have also been published.