Daggerspell (1986) is a fantasy novel by American writer Katharine Kerr.
 Her first novel, it is also the first book in the Celtic themed, multi-reincarnational "Deverry cycle".
Katharine Kerr (born 1944) is an American science fiction and fantasy novelist, best known for her series of Celtic-influenced high fantasy novels set in the fictional land of Deverry.
Engine Summer is a novel by American writer John Crowley, published in 1979 by Doubleday.
 It was nominated for the 1980 National Book Award for hardcover science fiction, as well as both the British Fantasy and John W. Campbell Awards the same year.
 It was rewritten from Crowley's unpublished first novel, "Learning to Live With It."
This article lists some of the major characters in the Deverry Cycle by Katharine Kerr.
Daemonomania is a 2000 Modern Fantasy novel by John Crowley.
 It is Crowley's seventh novel, and as the third novel in Crowley's Ægypt Sequence, a sequel to Crowley's 1994 novel "Love & Sleep".
 The novel follows protagonist Pierce Moffett as he continues his book project begun in "The Solitudes" about the Renaissance and Hermeticism, while dealing with a stormy relationship with his girlfriend Rosie Ryder.
The Solitudes (originally titled Ægypt contrary to Crowley's wishes) is a 1987 modern fantasy novel by John Crowley.
 It is Crowley's fifth published novel and the first novel in the four-volume Ægypt series.
 The novel follows Pierce Moffett, a college history professor in his retreat from ordinary, academic life to pastoral life of Faraway Hills.
 While in the area, Pierce comes up with a plan to write a book about Hermeticism, in the process finding several parallels with his own project and that of the nearly-forgotten local novelist Fellowes Kraft.
The Deverry Cycle is a series of Celtic fantasy novels by Katharine Kerr set in the fictional land of Deverry.
 As of November 2009, fifteen books have been published in the series.
Love & Sleep is a 1994 Modern Fantasy novel by John Crowley.
 It is the second novel in Crowley's Ægypt Sequence and a sequel to Crowley's 1987 novel "The Solitudes".
 In it, the protagonist Pierce Moffett continues his book project begun in "The Solitudes", exploring especially the relevance of systems of thought, even those magical and supposedly obsolete in writing a non-fiction book about the Renaissance and Hermeticism.
John Crowley (born 19 August 1969) is an Irish film and theatre director.
 He is best known for directing "Brooklyn" (2015) and his feature film debut "Intermission" (2003).
 He is a brother of designer Bob Crowley.
John Crowley (born December 1, 1942) is an American author of fantasy, science fiction and mainstream fiction.
 He studied at Indiana University and has a second career as a documentary film writer.

Question: Are John Crowley and Katharine Kerr both Americans ?
Answer: yes