The many worlds of Poul Anderson.

Includes: "Foreword' (Roger Elwood) "Tomorrow's Children" (novelette) (Poul Anderson and F. N. Waldrop (uncredited)) "The Queen of Air and Darkness" (novella) (Poul Anderson) "Her Strong Enchantments Failing" (essay) (Patrick L. McGuire) "Epilogue" (novella) (Poul Anderson) "The Longest Voyage" (novelette) (Poul Anderson) "Challenge and Response" (essay) (Sandra Miesel) "Journeys End" (short story) (Poul Anderson) "A World Named Cleopatra" (essay) (Poul Anderson) "The Sheriff of Canyon Gulch" (novelette) (Poul Anderson and Gordon R. Dickson) "Day of Burning" (novelette) (Poul Anderson)

https://en.wikipedia.org/wiki/The_Many_Worlds_of_Poul_Anderson