Question: Whose son wrote I'm Losing You?

full_context: Document 1: Johanna von Trapp: Johanna von Trapp married Ernst Florian Winter on Easter Monday in 1948 and changed her middle name to Franziska. She had seven children: Ernst Leopold (1949–1969), Florian Stefan (1951), Johanna Maria (1952), Notburga Maria (1953), Hemma Maria (1956 ), Agathe (1957 ) and Severin (1959 ). She lived with her family – four daughters and three sons – in both the United States (West Nyack, NY) and Austria (Salzburg, Schloss Eichbuechl N.O.). With Ernst Florian, she raised her children in an organic homesteading tradition incorporating her rich European heritage into family life. She was known for her hosting, cooking and preparing feast day meals that often were shared with upwards of 50 guests. Her indomitable go-to spirit and ability to persevere through the loss of her oldest son from a car accident, showed her strength and resilience. She was known to her children as the story teller of her childhood life in the von Trapp family. Approaching life with a great sense of humor and faith, carried her throughout her life.
Document 2: Cleanup Time: "Cleanup Time" is a song written by John Lennon released on his 1980 album "Double Fantasy". It was also included on the compilation album "Lennon".
Document 3: Julia Murdock Smith: Julia Murdock Smith Dixon Middleton (May 1, 1831 – September 12, 1880) was an early member of the Latter Day Saint movement and the eldest surviving child and only daughter of Joseph Smith and Emma Hale Smith. She was adopted by the Smiths.
Document 4: I'm Losing You (John Lennon song): "I'm Losing You" is a song written by John Lennon and released on his 1980 album "Double Fantasy". It was completed in Bermuda in June 1980, after Lennon failed at an attempted telephone call to Yoko Ono. The song is also available on the 1982 compilation "The John Lennon Collection", the 1998 boxset "John Lennon Anthology", the one disc compilation "Wonsaponatime", the 2005 two disc compilation "" and in 2010 for the "Gimme Some Truth" album. The song was also featured in the 2005 musical "Lennon".
Document 5: Jack London: Jack London's mother, Flora Wellman, was the fifth and youngest child of Pennsylvania Canal builder Marshall Wellman and his first wife, Eleanor Garrett Jones.  Marshall Wellman was descended from Thomas Wellman, an early Puritan settler in the Massachusetts Bay Colony. Flora left Ohio and moved to the Pacific coast when her father remarried after her mother died. In San Francisco, Flora worked as a music teacher and spiritualist, claiming to channel the spirit of a Sauk chief, Black Hawk.Biographer Clarice Stasz and others believe London's father was astrologer William Chaney. Flora Wellman was living with Chaney in San Francisco when she became pregnant. Whether Wellman and Chaney were legally married is unknown. Most San Francisco civil records were destroyed by the extensive fires that followed the 1906 earthquake; nobody knows what name appeared on her son's birth certificate. Stasz notes that in his memoirs, Chaney refers to London's mother Flora Wellman as having been his "wife"; he also cites an advertisement in which Flora called herself "Florence Wellman Chaney".According to Flora Wellman's account, as recorded in the San Francisco Chronicle of June 4, 1875, Chaney demanded that she have an abortion. When she refused, he disclaimed responsibility for the child. In desperation, she shot herself. She was not seriously wounded, but she was temporarily deranged. After giving birth, Flora turned the baby over for care to Virginia Prentiss, an African-American woman and former slave. She was a major maternal figure throughout London's life. Late in 1876, Flora Wellman married John London, a partially disabled Civil War veteran, and brought her baby John, later known as Jack, to live with the newly married couple. The family moved around the San Francisco Bay Area before settling in Oakland, where London completed public grade school.
Document 6: Lennon Bermuda: Lennon Bermuda is a tribute album and book inspired by John Lennon’s visit to Bermuda in 1980, where he wrote a portion of his "Double Fantasy" album. The "Lennon Bermuda" boxed set comprises two discs by various artists with a connection to Bermuda, including Yoko Ono, covering Lennon songs. There is also a book by author Scott Neil, illustrated by artist Graham Foster, describing Lennon’s stay on the island.
Document 7: Imagine (John Lennon album): Imagine is the second studio album by John Lennon after his departure from the Beatles. Recorded and released in 1971, the album's musical arrangements are more elaborate compared to the basic, small-group arrangements of his first album, "John Lennon/Plastic Ono Band".
Document 8: Julia Lennon: Julia Lennon (née Stanley; 12 March 1914 – 15 July 1958) was the mother of English musician John Lennon, who was born during her marriage to Alfred Lennon. After complaints to Liverpool's Social Services by her eldest sister, Mimi Smith (née Stanley), she handed over the care of her son to her sister. She later had one daughter after an affair with a Welsh soldier, but the baby was given up for adoption after pressure from her family. She then had two daughters, Julia and Jackie, with John 'Bobby' Dykins. She never divorced her husband, preferring to live as the common-law wife of Dykins for the rest of her life.
Document 9: I Found Out: "I Found Out" is a song by the English musician John Lennon from his 1970 album "John Lennon/Plastic Ono Band".
Document 10: Evelyn Einstein: Einstein was born in Chicago; after her birth she was adopted by Hans Albert Einstein. Towards the end of her life, she recounted that as a child she was told she was an illegitimate daughter of Albert Einstein and a ballet dancer; however, she had no documentation supporting this claim. She obtained a Master's degree in Medieval literature at University of California, Berkeley. She was married to Grover Krantz for 13 years from 1964 to about 1977. She then worked briefly as an animal control officer, as a cult deprogrammer, and as a Berkeley, California, reserve police officer.
Document 11: She's Always a Woman: The song was released in 1977, following several other hits from The Stranger including ``Just the Way You Are '',`` Movin 'Out (Anthony's Song)'' and ``Only the Good Die Young ''. Musically, Joel has said that he was influenced by Gordon Lightfoot and his mellow acoustic guitar ballads. It is a love song that Joel wrote for his then wife, Elizabeth Weber. Elizabeth had taken over management of Joel's career, and was able to put his financial affairs in order after Joel had signed some bad deals and contracts. She was a tough and savvy negotiator who could`` wound with her eyes'' or ``steal like a thief '', but would`` never give in''. Because of her tough - as - nails negotiating style, many business adversaries thought she was ``unfeminine, ''but to Joel, she was always a woman. The two eventually divorced in 1982.
Document 12: Grow Old with Me: ``Grow Old with Me ''is one of the final songs written by John Lennon. It was recorded by Lennon as a demo while in Bermuda in 1980, and later appeared on the posthumous album, Milk and Honey in 1984. It was also considered as a possible reunion single by his former bandmates during the making of The Beatles Anthology.
Document 13: Mother (John Lennon song): "Mother" is a song by English musician John Lennon, first released on his 1970 album "John Lennon/Plastic Ono Band". An edited version of the song was issued as a single in the United States on Apple Records, on 28 December 1970. The single edit runs 1:41 shorter than the album due to removing the tolling bells that start the song and a quicker fade-out. The B-side features "Why" by Yoko Ono. The song peaked in the United States at number 19 on the "Cashbox" Top 100 and number 43 on the "Billboard" Hot 100.
Document 14: Milk and Honey (album): Milk and Honey is the sixth and final album by John Lennon and Yoko Ono released in 1984. Following the compilation "The John Lennon Collection", it is Lennon's eighth and final studio album, and the first posthumous release of new Lennon music, having been recorded in the last months of his life during and following the sessions for his 1980 album "Double Fantasy". It was assembled by Yoko Ono in association with the Geffen label.
Document 15: Julia Baird: Julia Baird (née Dykins; born 5 March 1947) is a British retired teacher and author. She is the younger half-sister of English musician John Lennon, and is the eldest daughter of his mother Julia Lennon (12 March 1914 – 15 July 1958) and John 'Bobby' Albert Dykins (1918 – December 1965). She also has an older half-sister, Ingrid Pedersen. Her younger sister is Jacqueline 'Jackie' Dykins (born 26 October 1949).
ground_truth: Alfred Lennon
sub_queries: I'm Losing You >> performer Answer: John Lennon
John Lennon >> father Answer: Alfred Lennon